Ivanovski, Valentin N.

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Authority KeyName Variants
orcid::0000-0001-7036-7631
  • Ivanovski, Valentin N. (43)
Projects
Investigation of intermetallics and semiconductors and possible application in renewable energy sources Nanostructured multifunctional materials and nanocomposites
Magnetic and radionuclide labeled nanostructured materials for medical applications Optoelectronics nanodimension systems - the rout towards applications
Molecular designing of nanoparticles with controlled morphological and physicochemical characteristics and functional materials based on them Strukturne, dinamičke i spektroskopske karakteristike intermetalika i poluprovodnika
Bilateral Cooperation Project between the Republic of Slovenia and the Republic of Serbia U.S. DOE-BES, Division of Materials Science and Engineering [DE-SC0012704]
Bilateral collaboration INCDIE ICPE-CA Bucharest JINR Dubna [04-4-1069-2009/2011, agreement no. 3887-4-09/11/2009] Center for Emergent Superconductivity, an Energy Frontier Research Center - U.S. DOE, Office of Basic Energy Sciences, U.S. DOE [DEAC02-98CH10886], USDOE BES, Division of Materials Science and Engineering [DEAC02-98CH10886], Henan University
Czech Ministry of Education, Youth and Sports [1M0512] Nuclear physics, methods and application
Physical processes in the synthesis of advanced nanostructured materials Physics of nanostructured oxide materials and strongly correlated systems
Minerals of Serbia: composition, genesis, application and contribution to the environmental sustainability Synthesis, processing and characterization of nanostructured materials for application in the field of energy, mechanical engineering, environmental protection and biomedicine
Lithium-ion batteries and fuel cells - research and development Synthesis, processing and applications of nanostructured multifunctional materials with defined properties
Cleaner production: power plant wastewater treatment process development Ministry of Science and Technology of China [2016YFA0300504]
National Natural Science Foundation of China [11574394] National Natural Science Foundation of China [11774423]
National Natural Science Foundation of China [11822412] NVIDIA Corporation via their GPU Grant Program
Office of Basic Energy Sciences, U.S. Department of Energy [DE-Ac02-98CH10886] Polish Academy of Science, Institute of Physics Belgrade
Republic of Slovenia, Republic of Serbia [651-03-1251/2012-09/05] Romanian grant [PNII 12-086/2008]
Serbian MSTD [141047], SASA [F-134] US Department of Energy (DOE) by Bookcases Science Associates [DE-Ac02-98CH10886], DOE Office of Basic Energy Sciences, DOE [DE-AC52-06NA25396]

Author's Bibliography

Structural, microstructural and mechanical properties of sintered iron-doped mullite

Ilić, Svetlana M.; Ivanovski, Valentin N.; Radovanović, Željko; Egelja, Adela; Kokunešoski, Maja; Šaponjić, Aleksandra; Matović, Branko

(2020)

TY  - JOUR
AU  - Ilić, Svetlana M.
AU  - Ivanovski, Valentin N.
AU  - Radovanović, Željko
AU  - Egelja, Adela
AU  - Kokunešoski, Maja
AU  - Šaponjić, Aleksandra
AU  - Matović, Branko
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8942
AB  - The study of an effect of iron doping on the structural, microstructural and mechanical properties of sintered iron-doped mullite is presented. The results of phase composition, performed in detail by Mössbauer spectroscopy and XRD analysis, revealed that all added iron was inside the mullite lattice forming the single phase up to 12% by weight of Fe2O3 and 1300 °C. Samples, which were processed at 1550 °C, contained secondary phases, hematite or magnetite, regardless of the amount of added iron. Furthermore, the addition of iron decreases the values of relative linear shrinkage comparing to the values of undoped one (~18%) while the densities of the sintered samples rise as well as their values of microhardness. Even though the density values were not too high (90 TD%), the obtained values of microhardness were excellent, 1634 HV0.1 for maximum iron content due to the characteristic mullite microstructure.
T2  - Materials Science and Engineering: B
T1  - Structural, microstructural and mechanical properties of sintered iron-doped mullite
VL  - 256
SP  - 114543
DO  - 10.1016/j.mseb.2020.114543
ER  - 
@article{
author = "Ilić, Svetlana M. and Ivanovski, Valentin N. and Radovanović, Željko and Egelja, Adela and Kokunešoski, Maja and Šaponjić, Aleksandra and Matović, Branko",
year = "2020",
url = "https://vinar.vin.bg.ac.rs/handle/123456789/8942",
abstract = "The study of an effect of iron doping on the structural, microstructural and mechanical properties of sintered iron-doped mullite is presented. The results of phase composition, performed in detail by Mössbauer spectroscopy and XRD analysis, revealed that all added iron was inside the mullite lattice forming the single phase up to 12% by weight of Fe2O3 and 1300 °C. Samples, which were processed at 1550 °C, contained secondary phases, hematite or magnetite, regardless of the amount of added iron. Furthermore, the addition of iron decreases the values of relative linear shrinkage comparing to the values of undoped one (~18%) while the densities of the sintered samples rise as well as their values of microhardness. Even though the density values were not too high (90 TD%), the obtained values of microhardness were excellent, 1634 HV0.1 for maximum iron content due to the characteristic mullite microstructure.",
journal = "Materials Science and Engineering: B",
title = "Structural, microstructural and mechanical properties of sintered iron-doped mullite",
volume = "256",
pages = "114543",
doi = "10.1016/j.mseb.2020.114543"
}
Ilić, S. M., Ivanovski, V. N., Radovanović, Ž., Egelja, A., Kokunešoski, M., Šaponjić, A.,& Matović, B. (2020). Structural, microstructural and mechanical properties of sintered iron-doped mullite.
Materials Science and Engineering: B, 256, 114543.
https://doi.org/10.1016/j.mseb.2020.114543
Ilić SM, Ivanovski VN, Radovanović Ž, Egelja A, Kokunešoski M, Šaponjić A, Matović B. Structural, microstructural and mechanical properties of sintered iron-doped mullite. Materials Science and Engineering: B. 2020;256:114543
Ilić Svetlana M., Ivanovski Valentin N., Radovanović Željko, Egelja Adela, Kokunešoski Maja, Šaponjić Aleksandra, Matović Branko, "Structural, microstructural and mechanical properties of sintered iron-doped mullite" Materials Science and Engineering: B, 256 (2020):114543,
https://doi.org/10.1016/j.mseb.2020.114543 .
1
1
1

Ab initio calculations of the optical and electronic properties of Bi2WO6 doped with Mo, Cr, Fe, and Zn on the W–lattice site

Koteski, Vasil J.; Belošević-Čavor, Jelena; Ivanovski, Valentin N.; Umićević, Ana; Toprek, Dragan

(2020)

TY  - JOUR
AU  - Koteski, Vasil J.
AU  - Belošević-Čavor, Jelena
AU  - Ivanovski, Valentin N.
AU  - Umićević, Ana
AU  - Toprek, Dragan
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8889
AB  - Substitutionally doped Bi2W1-xMxO6 (M = Mo, Cr, Fe, Zn; x = 0.125, 0,25, 0.5) is investigated using the density functional theory (DFT). For all the investigated transition metal dopants, the optical properties in the visible light range are improved over the undoped Bi2WO6. Irrespective of concentration, the lattice relaxation around the dopants is constrained to the first coordination shell. Mo, Fe, and Cr introduce localized defect states in the band gap, contributing to band gap narrowing. The localized states are hybridized between the impurity d–bands and host W 5d–and O 2p–states. Zn facilitates the reduction of the band gap by inducing a shift of the states near the top of the valence band toward higher energies. Our results suggest that Zn doping on the W lattice site may improve the photocatalytic properties of Bi2WO6 more than the other dopants.
T2  - Applied Surface Science
T1  - Ab initio calculations of the optical and electronic properties of Bi2WO6 doped with Mo, Cr, Fe, and Zn on the W–lattice site
VL  - 515
SP  - 146036
DO  - 10.1016/j.apsusc.2020.146036
ER  - 
@article{
author = "Koteski, Vasil J. and Belošević-Čavor, Jelena and Ivanovski, Valentin N. and Umićević, Ana and Toprek, Dragan",
year = "2020",
url = "https://vinar.vin.bg.ac.rs/handle/123456789/8889",
abstract = "Substitutionally doped Bi2W1-xMxO6 (M = Mo, Cr, Fe, Zn; x = 0.125, 0,25, 0.5) is investigated using the density functional theory (DFT). For all the investigated transition metal dopants, the optical properties in the visible light range are improved over the undoped Bi2WO6. Irrespective of concentration, the lattice relaxation around the dopants is constrained to the first coordination shell. Mo, Fe, and Cr introduce localized defect states in the band gap, contributing to band gap narrowing. The localized states are hybridized between the impurity d–bands and host W 5d–and O 2p–states. Zn facilitates the reduction of the band gap by inducing a shift of the states near the top of the valence band toward higher energies. Our results suggest that Zn doping on the W lattice site may improve the photocatalytic properties of Bi2WO6 more than the other dopants.",
journal = "Applied Surface Science",
title = "Ab initio calculations of the optical and electronic properties of Bi2WO6 doped with Mo, Cr, Fe, and Zn on the W–lattice site",
volume = "515",
pages = "146036",
doi = "10.1016/j.apsusc.2020.146036"
}
Koteski, V. J., Belošević-Čavor, J., Ivanovski, V. N., Umićević, A.,& Toprek, D. (2020). Ab initio calculations of the optical and electronic properties of Bi2WO6 doped with Mo, Cr, Fe, and Zn on the W–lattice site.
Applied Surface Science, 515, 146036.
https://doi.org/10.1016/j.apsusc.2020.146036
Koteski VJ, Belošević-Čavor J, Ivanovski VN, Umićević A, Toprek D. Ab initio calculations of the optical and electronic properties of Bi2WO6 doped with Mo, Cr, Fe, and Zn on the W–lattice site. Applied Surface Science. 2020;515:146036
Koteski Vasil J., Belošević-Čavor Jelena, Ivanovski Valentin N., Umićević Ana, Toprek Dragan, "Ab initio calculations of the optical and electronic properties of Bi2WO6 doped with Mo, Cr, Fe, and Zn on the W–lattice site" Applied Surface Science, 515 (2020):146036,
https://doi.org/10.1016/j.apsusc.2020.146036 .
3
2
2

Fe0.36(4)Pd 0.64(4)Se 2 : Magnetic Spin-Glass Polymorph of FeSe2 and PdSe2 Stable at Ambient Pressure

Tian, Jianjun; Ivanovski, Valentin N.; Szalda, David; Lei, Hechang; Wang, Aifeng; Liu, Yu; Zhang, Weifeng; Koteski, Vasil J.; Petrović, Čedomir

(2019)

TY  - JOUR
AU  - Tian, Jianjun
AU  - Ivanovski, Valentin N.
AU  - Szalda, David
AU  - Lei, Hechang
AU  - Wang, Aifeng
AU  - Liu, Yu
AU  - Zhang, Weifeng
AU  - Koteski, Vasil J.
AU  - Petrović, Čedomir
PY  - 2019
UR  - http://pubs.acs.org/doi/10.1021/acs.inorgchem.8b03089
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/8082
AB  - We report the synthesis and characterization of Fe 0.36(4) Pd 0.64(4) Se 2 with a pyrite-type structure. Fe 0.36(4) Pd 0.64(4) Se 2 was synthesized using ambient pressure flux crystal growth methods even though the space group Pa3 is high-pressure polymorph for both FeSe 2 and PdSe 2 . Combined experimental and theoretical analysis reveal magnetic spin glass state below 23 K in 1000 Oe that stems from random Fe/Pd occupancies on the same atomic site. The frozen-in magnetic randomness contributes significantly to electronic transport. Electronic structure calculations confirm dominant d-electron character of hybridized bands and large density of states near the Fermi level. Flux-grown single crystal alloys in Pd-Fe-Se atomic system therefore open new pathway for exploring different polymorphs in crystal structures and their novel properties. © 2019 American Chemical Society.
T2  - Inorganic Chemistry
T1  - Fe0.36(4)Pd 0.64(4)Se 2 : Magnetic Spin-Glass Polymorph of FeSe2 and PdSe2 Stable at Ambient Pressure
VL  - 58
IS  - 5
SP  - 3107
EP  - 3114
DO  - 10.1021/acs.inorgchem.8b03089
ER  - 
@article{
author = "Tian, Jianjun and Ivanovski, Valentin N. and Szalda, David and Lei, Hechang and Wang, Aifeng and Liu, Yu and Zhang, Weifeng and Koteski, Vasil J. and Petrović, Čedomir",
year = "2019",
url = "http://pubs.acs.org/doi/10.1021/acs.inorgchem.8b03089, http://vinar.vin.bg.ac.rs/handle/123456789/8082",
abstract = "We report the synthesis and characterization of Fe 0.36(4) Pd 0.64(4) Se 2 with a pyrite-type structure. Fe 0.36(4) Pd 0.64(4) Se 2 was synthesized using ambient pressure flux crystal growth methods even though the space group Pa3 is high-pressure polymorph for both FeSe 2 and PdSe 2 . Combined experimental and theoretical analysis reveal magnetic spin glass state below 23 K in 1000 Oe that stems from random Fe/Pd occupancies on the same atomic site. The frozen-in magnetic randomness contributes significantly to electronic transport. Electronic structure calculations confirm dominant d-electron character of hybridized bands and large density of states near the Fermi level. Flux-grown single crystal alloys in Pd-Fe-Se atomic system therefore open new pathway for exploring different polymorphs in crystal structures and their novel properties. © 2019 American Chemical Society.",
journal = "Inorganic Chemistry",
title = "Fe0.36(4)Pd 0.64(4)Se 2 : Magnetic Spin-Glass Polymorph of FeSe2 and PdSe2 Stable at Ambient Pressure",
volume = "58",
number = "5",
pages = "3107-3114",
doi = "10.1021/acs.inorgchem.8b03089"
}
Tian, J., Ivanovski, V. N., Szalda, D., Lei, H., Wang, A., Liu, Y., Zhang, W., Koteski, V. J.,& Petrović, Č. (2019). Fe0.36(4)Pd 0.64(4)Se 2 : Magnetic Spin-Glass Polymorph of FeSe2 and PdSe2 Stable at Ambient Pressure.
Inorganic Chemistry, 58(5), 3107-3114.
https://doi.org/10.1021/acs.inorgchem.8b03089
Tian J, Ivanovski VN, Szalda D, Lei H, Wang A, Liu Y, Zhang W, Koteski VJ, Petrović Č. Fe0.36(4)Pd 0.64(4)Se 2 : Magnetic Spin-Glass Polymorph of FeSe2 and PdSe2 Stable at Ambient Pressure. Inorganic Chemistry. 2019;58(5):3107-3114
Tian Jianjun, Ivanovski Valentin N., Szalda David, Lei Hechang, Wang Aifeng, Liu Yu, Zhang Weifeng, Koteski Vasil J., Petrović Čedomir, "Fe0.36(4)Pd 0.64(4)Se 2 : Magnetic Spin-Glass Polymorph of FeSe2 and PdSe2 Stable at Ambient Pressure" Inorganic Chemistry, 58, no. 5 (2019):3107-3114,
https://doi.org/10.1021/acs.inorgchem.8b03089 .
2
1
2

Characterization of LiFePO4 samples obtained by pulse combustion under various conditions of synthesis

Lazarević, Zorica Ž.; Križan, Gregor; Križan, Janez; Milutinović, Aleksandra N.; Ivanovski, Valentin N.; Mitrić, Miodrag; Gilić, Martina; Umićević, Ana; Kuryliszyn-Kudelska, Izabela; Romčević, Nebojša Ž.

(2019)

TY  - JOUR
AU  - Lazarević, Zorica Ž.
AU  - Križan, Gregor
AU  - Križan, Janez
AU  - Milutinović, Aleksandra N.
AU  - Ivanovski, Valentin N.
AU  - Mitrić, Miodrag
AU  - Gilić, Martina
AU  - Umićević, Ana
AU  - Kuryliszyn-Kudelska, Izabela
AU  - Romčević, Nebojša Ž.
PY  - 2019
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/8501
AB  - Lithium iron phosphate (LiFePO4, LFP) is one of the widely used cathode materials for rechargeable lithium ion batteries. LFP batteries are widely used for electric vehicles and backup power due to their important advantages such as low cost, lifetime, efficiency, and reliability. There are still several technical challenges that need to be addressed: The increase of energy density or further reduction of their final cost. This paper concerned with the characterization of carbon coated LiFePO4 nanopowder cathode materials produced under different conditions by pulse combustion for providing energy to the reactor for the synthesis. The reactor was built according to the principles of the thermoacoustic burner on the basis of the Helmholtz resonator. The investigated nanopowders are synthesized by complete and incomplete combustion and calcined at 700 °C. The obtained samples were characterized by X-ray diffraction, Fourier transform infrared, Raman, and Mössbauer spectroscopy. Observed low-Temperature magnetic phase transitions definitively identified the crystal phases. The morphology of samples was controlled by scanning electron microscopy. The aim of this work is to show that it is possible to achieve a desired crystal phase by pulse combustion in a relatively cheap and fast way. The extremely rapid synthesis of almost pure phase material is possible due to the reduction in size of interacting particles and to an enormous number of collisions between them as a result of strong turbulent flow associated with explosive combustion. © 2019 Author(s).
T2  - Journal of Applied Physics
T1  - Characterization of LiFePO4 samples obtained by pulse combustion under various conditions of synthesis
VL  - 126
IS  - 8
SP  - 085109
DO  - 10.1063/1.5100358
ER  - 
@article{
author = "Lazarević, Zorica Ž. and Križan, Gregor and Križan, Janez and Milutinović, Aleksandra N. and Ivanovski, Valentin N. and Mitrić, Miodrag and Gilić, Martina and Umićević, Ana and Kuryliszyn-Kudelska, Izabela and Romčević, Nebojša Ž.",
year = "2019",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/8501",
abstract = "Lithium iron phosphate (LiFePO4, LFP) is one of the widely used cathode materials for rechargeable lithium ion batteries. LFP batteries are widely used for electric vehicles and backup power due to their important advantages such as low cost, lifetime, efficiency, and reliability. There are still several technical challenges that need to be addressed: The increase of energy density or further reduction of their final cost. This paper concerned with the characterization of carbon coated LiFePO4 nanopowder cathode materials produced under different conditions by pulse combustion for providing energy to the reactor for the synthesis. The reactor was built according to the principles of the thermoacoustic burner on the basis of the Helmholtz resonator. The investigated nanopowders are synthesized by complete and incomplete combustion and calcined at 700 °C. The obtained samples were characterized by X-ray diffraction, Fourier transform infrared, Raman, and Mössbauer spectroscopy. Observed low-Temperature magnetic phase transitions definitively identified the crystal phases. The morphology of samples was controlled by scanning electron microscopy. The aim of this work is to show that it is possible to achieve a desired crystal phase by pulse combustion in a relatively cheap and fast way. The extremely rapid synthesis of almost pure phase material is possible due to the reduction in size of interacting particles and to an enormous number of collisions between them as a result of strong turbulent flow associated with explosive combustion. © 2019 Author(s).",
journal = "Journal of Applied Physics",
title = "Characterization of LiFePO4 samples obtained by pulse combustion under various conditions of synthesis",
volume = "126",
number = "8",
pages = "085109",
doi = "10.1063/1.5100358"
}
Lazarević, Z. Ž., Križan, G., Križan, J., Milutinović, A. N., Ivanovski, V. N., Mitrić, M., Gilić, M., Umićević, A., Kuryliszyn-Kudelska, I.,& Romčević, N. Ž. (2019). Characterization of LiFePO4 samples obtained by pulse combustion under various conditions of synthesis.
Journal of Applied Physics, 126(8), 085109.
https://doi.org/10.1063/1.5100358
Lazarević ZŽ, Križan G, Križan J, Milutinović AN, Ivanovski VN, Mitrić M, Gilić M, Umićević A, Kuryliszyn-Kudelska I, Romčević NŽ. Characterization of LiFePO4 samples obtained by pulse combustion under various conditions of synthesis. Journal of Applied Physics. 2019;126(8):085109
Lazarević Zorica Ž., Križan Gregor, Križan Janez, Milutinović Aleksandra N., Ivanovski Valentin N., Mitrić Miodrag, Gilić Martina, Umićević Ana, Kuryliszyn-Kudelska Izabela, Romčević Nebojša Ž., "Characterization of LiFePO4 samples obtained by pulse combustion under various conditions of synthesis" Journal of Applied Physics, 126, no. 8 (2019):085109,
https://doi.org/10.1063/1.5100358 .

Structural and electrochemical properties of the Li2FeP2O7/C composite prepared using soluble methylcellulose

Jugović, Dragana; Mitrić, Miodrag; Milović, Miloš; Ivanovski, Valentin N.; Škapin, Srečo Davor; Dojčinović, Biljana P.; Uskoković, Dragan

(2019)

TY  - JOUR
AU  - Jugović, Dragana
AU  - Mitrić, Miodrag
AU  - Milović, Miloš
AU  - Ivanovski, Valentin N.
AU  - Škapin, Srečo Davor
AU  - Dojčinović, Biljana P.
AU  - Uskoković, Dragan
PY  - 2019
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/8052
AB  - A new method involving the homogeneous dispersion of precursor compounds inside a methylcellulose matrix is used for the synthesis of a composite powder of Li 2 FeP 2 O 7 and carbon. The properties of carbon-containing and carbon-free powders are studied by X-ray powder diffraction (XRD) including Rietveld refinement, Mössbauer spectroscopy, Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), galvanostatic cycling, and electrochemical impedance spectroscopy (EIS). The structure of both powders is refined in a monoclinic framework (space group P2 1 /c). The structural refinement and Mössbauer spectroscopy reveal different degrees of partial occupancy of mixed-occupied sites by lithium. Electrochemical measurements show that the in situ formation of carbon improves capacity (90% of 1-electron theoretical capacity) through decreased charge-transfer resistance. © 2019 Elsevier B.V.
T2  - Journal of Alloys and Compounds
T1  - Structural and electrochemical properties of the Li2FeP2O7/C composite prepared using soluble methylcellulose
VL  - 786
SP  - 912
EP  - 919
DO  - 10.1016/j.jallcom.2019.01.392
ER  - 
@article{
author = "Jugović, Dragana and Mitrić, Miodrag and Milović, Miloš and Ivanovski, Valentin N. and Škapin, Srečo Davor and Dojčinović, Biljana P. and Uskoković, Dragan",
year = "2019",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/8052",
abstract = "A new method involving the homogeneous dispersion of precursor compounds inside a methylcellulose matrix is used for the synthesis of a composite powder of Li 2 FeP 2 O 7 and carbon. The properties of carbon-containing and carbon-free powders are studied by X-ray powder diffraction (XRD) including Rietveld refinement, Mössbauer spectroscopy, Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), galvanostatic cycling, and electrochemical impedance spectroscopy (EIS). The structure of both powders is refined in a monoclinic framework (space group P2 1 /c). The structural refinement and Mössbauer spectroscopy reveal different degrees of partial occupancy of mixed-occupied sites by lithium. Electrochemical measurements show that the in situ formation of carbon improves capacity (90% of 1-electron theoretical capacity) through decreased charge-transfer resistance. © 2019 Elsevier B.V.",
journal = "Journal of Alloys and Compounds",
title = "Structural and electrochemical properties of the Li2FeP2O7/C composite prepared using soluble methylcellulose",
volume = "786",
pages = "912-919",
doi = "10.1016/j.jallcom.2019.01.392"
}
Jugović, D., Mitrić, M., Milović, M., Ivanovski, V. N., Škapin, S. D., Dojčinović, B. P.,& Uskoković, D. (2019). Structural and electrochemical properties of the Li2FeP2O7/C composite prepared using soluble methylcellulose.
Journal of Alloys and Compounds, 786, 912-919.
https://doi.org/10.1016/j.jallcom.2019.01.392
Jugović D, Mitrić M, Milović M, Ivanovski VN, Škapin SD, Dojčinović BP, Uskoković D. Structural and electrochemical properties of the Li2FeP2O7/C composite prepared using soluble methylcellulose. Journal of Alloys and Compounds. 2019;786:912-919
Jugović Dragana, Mitrić Miodrag, Milović Miloš, Ivanovski Valentin N., Škapin Srečo Davor, Dojčinović Biljana P., Uskoković Dragan, "Structural and electrochemical properties of the Li2FeP2O7/C composite prepared using soluble methylcellulose" Journal of Alloys and Compounds, 786 (2019):912-919,
https://doi.org/10.1016/j.jallcom.2019.01.392 .
2
1
3

Structural and electrochemical properties of the Li2FeP2O7/C composite prepared using soluble methylcellulose

Jugović, Dragana; Mitrić, Miodrag; Milović, Miloš; Ivanovski, Valentin N.; Škapin, Srečo Davor; Dojčinović, Biljana P.; Uskoković, Dragan

(2019)

TY  - JOUR
AU  - Jugović, Dragana
AU  - Mitrić, Miodrag
AU  - Milović, Miloš
AU  - Ivanovski, Valentin N.
AU  - Škapin, Srečo Davor
AU  - Dojčinović, Biljana P.
AU  - Uskoković, Dragan
PY  - 2019
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/8047
AB  - A new method involving the homogeneous dispersion of precursor compounds inside a methylcellulose matrix is used for the synthesis of a composite powder of Li 2 FeP 2 O 7 and carbon. The properties of carbon-containing and carbon-free powders are studied by X-ray powder diffraction (XRD) including Rietveld refinement, Mössbauer spectroscopy, Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), galvanostatic cycling, and electrochemical impedance spectroscopy (EIS). The structure of both powders is refined in a monoclinic framework (space group P2 1 /c). The structural refinement and Mössbauer spectroscopy reveal different degrees of partial occupancy of mixed-occupied sites by lithium. Electrochemical measurements show that the in situ formation of carbon improves capacity (90% of 1-electron theoretical capacity) through decreased charge-transfer resistance. © 2019 Elsevier B.V.
T2  - Journal of Alloys and Compounds
T1  - Structural and electrochemical properties of the Li2FeP2O7/C composite prepared using soluble methylcellulose
VL  - 786
SP  - 912
EP  - 919
DO  - 10.1016/j.jallcom.2019.01.392
ER  - 
@article{
author = "Jugović, Dragana and Mitrić, Miodrag and Milović, Miloš and Ivanovski, Valentin N. and Škapin, Srečo Davor and Dojčinović, Biljana P. and Uskoković, Dragan",
year = "2019",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/8047",
abstract = "A new method involving the homogeneous dispersion of precursor compounds inside a methylcellulose matrix is used for the synthesis of a composite powder of Li 2 FeP 2 O 7 and carbon. The properties of carbon-containing and carbon-free powders are studied by X-ray powder diffraction (XRD) including Rietveld refinement, Mössbauer spectroscopy, Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), galvanostatic cycling, and electrochemical impedance spectroscopy (EIS). The structure of both powders is refined in a monoclinic framework (space group P2 1 /c). The structural refinement and Mössbauer spectroscopy reveal different degrees of partial occupancy of mixed-occupied sites by lithium. Electrochemical measurements show that the in situ formation of carbon improves capacity (90% of 1-electron theoretical capacity) through decreased charge-transfer resistance. © 2019 Elsevier B.V.",
journal = "Journal of Alloys and Compounds",
title = "Structural and electrochemical properties of the Li2FeP2O7/C composite prepared using soluble methylcellulose",
volume = "786",
pages = "912-919",
doi = "10.1016/j.jallcom.2019.01.392"
}
Jugović, D., Mitrić, M., Milović, M., Ivanovski, V. N., Škapin, S. D., Dojčinović, B. P.,& Uskoković, D. (2019). Structural and electrochemical properties of the Li2FeP2O7/C composite prepared using soluble methylcellulose.
Journal of Alloys and Compounds, 786, 912-919.
https://doi.org/10.1016/j.jallcom.2019.01.392
Jugović D, Mitrić M, Milović M, Ivanovski VN, Škapin SD, Dojčinović BP, Uskoković D. Structural and electrochemical properties of the Li2FeP2O7/C composite prepared using soluble methylcellulose. Journal of Alloys and Compounds. 2019;786:912-919
Jugović Dragana, Mitrić Miodrag, Milović Miloš, Ivanovski Valentin N., Škapin Srečo Davor, Dojčinović Biljana P., Uskoković Dragan, "Structural and electrochemical properties of the Li2FeP2O7/C composite prepared using soluble methylcellulose" Journal of Alloys and Compounds, 786 (2019):912-919,
https://doi.org/10.1016/j.jallcom.2019.01.392 .
2
1
2

A study of defect structures in Fe-alloyed ZnO: Morphology, magnetism, and hyperfine interactions

Ivanovski, Valentin N.; Belošević-Čavor, Jelena; Rajić, Vladimir; Umićević, Ana; Marković, Smilja; Kusigerski, Vladan; Mitrić, Miodrag; Koteski, Vasil J.

(2019)

TY  - JOUR
AU  - Ivanovski, Valentin N.
AU  - Belošević-Čavor, Jelena
AU  - Rajić, Vladimir
AU  - Umićević, Ana
AU  - Marković, Smilja
AU  - Kusigerski, Vladan
AU  - Mitrić, Miodrag
AU  - Koteski, Vasil J.
PY  - 2019
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/8515
AB  - In order to study the effect of Fe cation substitution on the local structure, defect formation, and hyperfine interactions in ZnO, Mössbauer spectroscopy measurements of the microwave processed Zn 1 - x Fe x O (x = 0.05, 0.10, 0.15, and 0.20) nanoparticles, together with ab initio calculations, were performed. Complementary information on the distribution of particle size and morphology, as well as magnetic properties, were obtained by X-ray diffraction, transmission electron microscopy, and squid-magnetometry. The selected model for analyzing the Mössbauer spectra of our samples is a distribution of quadrupole splittings. The fitting model with two Lorentz doublets was rejected due to its failure to include larger doublets. The Fe 3 + ions do not yield magnetic ordering in the samples at room temperature. The results from first-principles calculations confirm that the major component of the Mössbauer spectra corresponds to the Fe-alloyed ZnO with Zn vacancy in the next nearest neighbor environment. The magnetic measurements are consistent with the description of the distribution of iron ions over the randomly formed clusters in the ZnO host lattice. While at room temperature all the samples are paramagnetic, magnetic interactions cause a transition into a cluster spin-glass state at low temperatures. © 2019 Author(s).
T2  - Journal of Applied Physics
T1  - A study of defect structures in Fe-alloyed ZnO: Morphology, magnetism, and hyperfine interactions
VL  - 126
IS  - 12
SP  - 125703
DO  - 10.1063/1.5095837
ER  - 
@article{
author = "Ivanovski, Valentin N. and Belošević-Čavor, Jelena and Rajić, Vladimir and Umićević, Ana and Marković, Smilja and Kusigerski, Vladan and Mitrić, Miodrag and Koteski, Vasil J.",
year = "2019",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/8515",
abstract = "In order to study the effect of Fe cation substitution on the local structure, defect formation, and hyperfine interactions in ZnO, Mössbauer spectroscopy measurements of the microwave processed Zn 1 - x Fe x O (x = 0.05, 0.10, 0.15, and 0.20) nanoparticles, together with ab initio calculations, were performed. Complementary information on the distribution of particle size and morphology, as well as magnetic properties, were obtained by X-ray diffraction, transmission electron microscopy, and squid-magnetometry. The selected model for analyzing the Mössbauer spectra of our samples is a distribution of quadrupole splittings. The fitting model with two Lorentz doublets was rejected due to its failure to include larger doublets. The Fe 3 + ions do not yield magnetic ordering in the samples at room temperature. The results from first-principles calculations confirm that the major component of the Mössbauer spectra corresponds to the Fe-alloyed ZnO with Zn vacancy in the next nearest neighbor environment. The magnetic measurements are consistent with the description of the distribution of iron ions over the randomly formed clusters in the ZnO host lattice. While at room temperature all the samples are paramagnetic, magnetic interactions cause a transition into a cluster spin-glass state at low temperatures. © 2019 Author(s).",
journal = "Journal of Applied Physics",
title = "A study of defect structures in Fe-alloyed ZnO: Morphology, magnetism, and hyperfine interactions",
volume = "126",
number = "12",
pages = "125703",
doi = "10.1063/1.5095837"
}
Ivanovski, V. N., Belošević-Čavor, J., Rajić, V., Umićević, A., Marković, S., Kusigerski, V., Mitrić, M.,& Koteski, V. J. (2019). A study of defect structures in Fe-alloyed ZnO: Morphology, magnetism, and hyperfine interactions.
Journal of Applied Physics, 126(12), 125703.
https://doi.org/10.1063/1.5095837
Ivanovski VN, Belošević-Čavor J, Rajić V, Umićević A, Marković S, Kusigerski V, Mitrić M, Koteski VJ. A study of defect structures in Fe-alloyed ZnO: Morphology, magnetism, and hyperfine interactions. Journal of Applied Physics. 2019;126(12):125703
Ivanovski Valentin N., Belošević-Čavor Jelena, Rajić Vladimir, Umićević Ana, Marković Smilja, Kusigerski Vladan, Mitrić Miodrag, Koteski Vasil J., "A study of defect structures in Fe-alloyed ZnO: Morphology, magnetism, and hyperfine interactions" Journal of Applied Physics, 126, no. 12 (2019):125703,
https://doi.org/10.1063/1.5095837 .
4
3
3

Effect of 5d transition metals doping on the photocatalytic properties of rutile TiO 2

Belošević-Čavor, Jelena; Koteski, Vasil J.; Umićević, Ana; Ivanovski, Valentin N.

(2018)

TY  - JOUR
AU  - Belošević-Čavor, Jelena
AU  - Koteski, Vasil J.
AU  - Umićević, Ana
AU  - Ivanovski, Valentin N.
PY  - 2018
UR  - http://linkinghub.elsevier.com/retrieve/pii/S0927025618303306
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7700
AB  - Density functional theory (DFT) calculations were performed to address the effects of 5d transition metals (TM) doping on the electronic structure properties of rutile TiO2, using both the modified Becke-Johnson (mBJ) and on-site hybrid functional. The calculations show that there is a reduction of band gap in almost all the investigated cases, except when TiO2is doped with Ta. Some of the investigated systems (Re, W, Os, Ir) exhibit pronounced spin polarization, mainly arising from the TM atoms. In addition, a large increase of band gap is observed, when switching from a 24-atoms to 48-atoms supercell, while further enlarging the supercell size doesn't affect the band gap significantly. Among the investigated transition metals, Pt and Ir are the best candidates for improving the photocatalytic properties of rutile TiO2through substitutional doping.
T2  - Computational Materials Science
T1  - Effect of 5d transition metals doping on the photocatalytic properties of rutile TiO 2
VL  - 151
SP  - 328
EP  - 337
DO  - 10.1016/j.commatsci.2018.05.022
ER  - 
@article{
author = "Belošević-Čavor, Jelena and Koteski, Vasil J. and Umićević, Ana and Ivanovski, Valentin N.",
year = "2018",
url = "http://linkinghub.elsevier.com/retrieve/pii/S0927025618303306, http://vinar.vin.bg.ac.rs/handle/123456789/7700",
abstract = "Density functional theory (DFT) calculations were performed to address the effects of 5d transition metals (TM) doping on the electronic structure properties of rutile TiO2, using both the modified Becke-Johnson (mBJ) and on-site hybrid functional. The calculations show that there is a reduction of band gap in almost all the investigated cases, except when TiO2is doped with Ta. Some of the investigated systems (Re, W, Os, Ir) exhibit pronounced spin polarization, mainly arising from the TM atoms. In addition, a large increase of band gap is observed, when switching from a 24-atoms to 48-atoms supercell, while further enlarging the supercell size doesn't affect the band gap significantly. Among the investigated transition metals, Pt and Ir are the best candidates for improving the photocatalytic properties of rutile TiO2through substitutional doping.",
journal = "Computational Materials Science",
title = "Effect of 5d transition metals doping on the photocatalytic properties of rutile TiO 2",
volume = "151",
pages = "328-337",
doi = "10.1016/j.commatsci.2018.05.022"
}
Belošević-Čavor, J., Koteski, V. J., Umićević, A.,& Ivanovski, V. N. (2018). Effect of 5d transition metals doping on the photocatalytic properties of rutile TiO 2.
Computational Materials Science, 151, 328-337.
https://doi.org/10.1016/j.commatsci.2018.05.022
Belošević-Čavor J, Koteski VJ, Umićević A, Ivanovski VN. Effect of 5d transition metals doping on the photocatalytic properties of rutile TiO 2. Computational Materials Science. 2018;151:328-337
Belošević-Čavor Jelena, Koteski Vasil J., Umićević Ana, Ivanovski Valentin N., "Effect of 5d transition metals doping on the photocatalytic properties of rutile TiO 2" Computational Materials Science, 151 (2018):328-337,
https://doi.org/10.1016/j.commatsci.2018.05.022 .
6
6
6

Efficient multistep arsenate removal onto magnetite modified fly ash

Karanac, Milica; Đolić, Maja B.; Veličković, Zlate S.; Kapidžić, Ana; Ivanovski, Valentin N.; Mitrić, Miodrag; Marinković, Aleksandar D.

(2018)

TY  - JOUR
AU  - Karanac, Milica
AU  - Đolić, Maja B.
AU  - Veličković, Zlate S.
AU  - Kapidžić, Ana
AU  - Ivanovski, Valentin N.
AU  - Mitrić, Miodrag
AU  - Marinković, Aleksandar D.
PY  - 2018
UR  - https://linkinghub.elsevier.com/retrieve/pii/S030147971830803X
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7875
AB  - The modification of the fly ash (FA) by magnetite (M) was performed to obtain FAM adsorbent with improved adsorption efficiency for arsenate removal from water. The novel low cost adsorbents are characterized by liquid nitrogen porosimetry (BET), scanning electron microscopy (SEM), X-ray diffraction (XRD), Mössbauer spectroscopy (MB) and Fourier transform infrared (FTIR) spectroscopy. The optimal conditions and key factors influencing the adsorbent synthesis are assessed using the response surface method (RSM). The adsorption experiment was carried out in a batch system by varying the contact time, temperature, pH, and mass of the adsorbent. The adsorption capacity of the FAM adsorbent for As(V), calculated by Langmuir model, was 19.14 mg g−1. The thermodynamic parameters showed spontaneity of adsorption with low endothermic character. The kinetic data followed the pseudo-second-order kinetic model (PSO), and Weber-Morris model indicated intra-particle diffusion as rate limiting step. Alternative to low desorption capability of the FAM was found by five consecutive adsorption/magnetite precipitation processes which gave exhausted layered adsorbent with 65.78 mg g−1 capacity. This research also has shed light on the mechanism of As(V)-ion adsorption, presenting a promising solution for the valorization of a widely abundant industrial waste. © 2018 Elsevier Ltd
T2  - Journal of Environmental Management
T1  - Efficient multistep arsenate removal onto magnetite modified fly ash
VL  - 224
SP  - 263
EP  - 276
DO  - 10.1016/j.jenvman.2018.07.051
ER  - 
@article{
author = "Karanac, Milica and Đolić, Maja B. and Veličković, Zlate S. and Kapidžić, Ana and Ivanovski, Valentin N. and Mitrić, Miodrag and Marinković, Aleksandar D.",
year = "2018",
url = "https://linkinghub.elsevier.com/retrieve/pii/S030147971830803X, http://vinar.vin.bg.ac.rs/handle/123456789/7875",
abstract = "The modification of the fly ash (FA) by magnetite (M) was performed to obtain FAM adsorbent with improved adsorption efficiency for arsenate removal from water. The novel low cost adsorbents are characterized by liquid nitrogen porosimetry (BET), scanning electron microscopy (SEM), X-ray diffraction (XRD), Mössbauer spectroscopy (MB) and Fourier transform infrared (FTIR) spectroscopy. The optimal conditions and key factors influencing the adsorbent synthesis are assessed using the response surface method (RSM). The adsorption experiment was carried out in a batch system by varying the contact time, temperature, pH, and mass of the adsorbent. The adsorption capacity of the FAM adsorbent for As(V), calculated by Langmuir model, was 19.14 mg g−1. The thermodynamic parameters showed spontaneity of adsorption with low endothermic character. The kinetic data followed the pseudo-second-order kinetic model (PSO), and Weber-Morris model indicated intra-particle diffusion as rate limiting step. Alternative to low desorption capability of the FAM was found by five consecutive adsorption/magnetite precipitation processes which gave exhausted layered adsorbent with 65.78 mg g−1 capacity. This research also has shed light on the mechanism of As(V)-ion adsorption, presenting a promising solution for the valorization of a widely abundant industrial waste. © 2018 Elsevier Ltd",
journal = "Journal of Environmental Management",
title = "Efficient multistep arsenate removal onto magnetite modified fly ash",
volume = "224",
pages = "263-276",
doi = "10.1016/j.jenvman.2018.07.051"
}
Karanac, M., Đolić, M. B., Veličković, Z. S., Kapidžić, A., Ivanovski, V. N., Mitrić, M.,& Marinković, A. D. (2018). Efficient multistep arsenate removal onto magnetite modified fly ash.
Journal of Environmental Management, 224, 263-276.
https://doi.org/10.1016/j.jenvman.2018.07.051
Karanac M, Đolić MB, Veličković ZS, Kapidžić A, Ivanovski VN, Mitrić M, Marinković AD. Efficient multistep arsenate removal onto magnetite modified fly ash. Journal of Environmental Management. 2018;224:263-276
Karanac Milica, Đolić Maja B., Veličković Zlate S., Kapidžić Ana, Ivanovski Valentin N., Mitrić Miodrag, Marinković Aleksandar D., "Efficient multistep arsenate removal onto magnetite modified fly ash" Journal of Environmental Management, 224 (2018):263-276,
https://doi.org/10.1016/j.jenvman.2018.07.051 .
1
13
10
10

Improving the photocatalytic properties of anatase TiO2(101) surface by co-doping with Cu and N: Ab initio study

Koteski, Vasil J.; Belošević-Čavor, Jelena; Umićević, Ana; Ivanovski, Valentin N.; Toprek, Dragan

(2017)

TY  - JOUR
AU  - Koteski, Vasil J.
AU  - Belošević-Čavor, Jelena
AU  - Umićević, Ana
AU  - Ivanovski, Valentin N.
AU  - Toprek, Dragan
PY  - 2017
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1721
AB  - Substitutionally and interstitially Cu/Nco-doped anatase TiO2(101) surface is investigated by using density functional theory (DFT) calculations. The results suggest improved visible light photocatalytic activity over undoped anatase TiO2. Sizable lattice relaxation around the dopants is observed, followed by a formation of N-O bond. Depending on the local arrangement of atoms, localized states above the valence band maximum, deep into the band gap, and below the conduction band minimum are found. In addition, our calculation also predict band gap narrowing. The hybridization of the Cu 3d and N 2p states within the band gap and the other electronic and optical properties suggest a synergistic effect of the dopants in the enhancement of the visible light absorption on the (101) anatase surface. (C) 2017 Elsevier B.V. All rights reserved.
T2  - Applied Surface Science
T1  - Improving the photocatalytic properties of anatase TiO2(101) surface by co-doping with Cu and N: Ab initio study
VL  - 425
SP  - 1095
EP  - 1100
DO  - 10.1016/j.apsusc.2017.07.064
ER  - 
@article{
author = "Koteski, Vasil J. and Belošević-Čavor, Jelena and Umićević, Ana and Ivanovski, Valentin N. and Toprek, Dragan",
year = "2017",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1721",
abstract = "Substitutionally and interstitially Cu/Nco-doped anatase TiO2(101) surface is investigated by using density functional theory (DFT) calculations. The results suggest improved visible light photocatalytic activity over undoped anatase TiO2. Sizable lattice relaxation around the dopants is observed, followed by a formation of N-O bond. Depending on the local arrangement of atoms, localized states above the valence band maximum, deep into the band gap, and below the conduction band minimum are found. In addition, our calculation also predict band gap narrowing. The hybridization of the Cu 3d and N 2p states within the band gap and the other electronic and optical properties suggest a synergistic effect of the dopants in the enhancement of the visible light absorption on the (101) anatase surface. (C) 2017 Elsevier B.V. All rights reserved.",
journal = "Applied Surface Science",
title = "Improving the photocatalytic properties of anatase TiO2(101) surface by co-doping with Cu and N: Ab initio study",
volume = "425",
pages = "1095-1100",
doi = "10.1016/j.apsusc.2017.07.064"
}
Koteski, V. J., Belošević-Čavor, J., Umićević, A., Ivanovski, V. N.,& Toprek, D. (2017). Improving the photocatalytic properties of anatase TiO2(101) surface by co-doping with Cu and N: Ab initio study.
Applied Surface Science, 425, 1095-1100.
https://doi.org/10.1016/j.apsusc.2017.07.064
Koteski VJ, Belošević-Čavor J, Umićević A, Ivanovski VN, Toprek D. Improving the photocatalytic properties of anatase TiO2(101) surface by co-doping with Cu and N: Ab initio study. Applied Surface Science. 2017;425:1095-1100
Koteski Vasil J., Belošević-Čavor Jelena, Umićević Ana, Ivanovski Valentin N., Toprek Dragan, "Improving the photocatalytic properties of anatase TiO2(101) surface by co-doping with Cu and N: Ab initio study" Applied Surface Science, 425 (2017):1095-1100,
https://doi.org/10.1016/j.apsusc.2017.07.064 .
6
5
7

Ab initio study of electronic and optical properties of Fe doped anatase TiO2 (101) surface

Toprek, Dragan; Koteski, Vasil J.; Belošević-Čavor, Jelena; Ivanovski, Valentin N.; Umićević, Ana

(2017)

TY  - JOUR
AU  - Toprek, Dragan
AU  - Koteski, Vasil J.
AU  - Belošević-Čavor, Jelena
AU  - Ivanovski, Valentin N.
AU  - Umićević, Ana
PY  - 2017
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1834
AB  - In this paper we investigated the effects of Fe-doping of the anatase TiO2 (1 0 1) surface on the crystal structure, electronic and optical properties, and impurity formation energy by means of density functional theory (DFT). The calculations were performed by the SIESTA DFT code and were carried out by using Troullier-Martins pseudopotentials for the 12-electron valence configuration (3s(2)3p(6)3d(2)4s(2)) of Ti atom, 6-electron valence configuration (2s(2)p(4)) of O atom and 8-electron valence configuration (3d(6)4s(2)) of Fe atom. We used a double- zeta basis set including polarization functions. All calculations were spin-polarized. The mechanism of narrowing the band gap and increasing the photocatalytic activity in the visible light region, of the doped TiO2 is discussed by investigating the density of state. The band gap decreases as the concentration of the dopant increases. The Partial Density of States (PDOS) is not the same in the case of spin-up state or spin-down state. Enhanced optical absorption, for light polarized in the z direction (parallel to the surface normal) is clearly observed for Fe doped as compared to the pure anatase TiO2 and the optical absorption is found to increase with the increase in the Fe concentration. The DFT results indicate that the source of the increasing photocatalytic activity in the visible light region of the Fe doped material is due to the introduction of additional electronic states within the band gap. Since the Fe atoms are more stable in Ti substitutional lattice positions for the entire range of Fermi energy E-F over the band gap, only this substitutional position is considered. We hope that our results will highlight a route to improved electronic and optical properties of anatase TiO2 for industrial applications. (C) 2017 Elsevier B.V. All rights reserved.
T2  - Computational and Theoretical Chemistry
T1  - Ab initio study of electronic and optical properties of Fe doped anatase TiO2 (101) surface
VL  - 1120
SP  - 17
EP  - 23
DO  - 10.1016/j.comptc.2017.09.024
ER  - 
@article{
author = "Toprek, Dragan and Koteski, Vasil J. and Belošević-Čavor, Jelena and Ivanovski, Valentin N. and Umićević, Ana",
year = "2017",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1834",
abstract = "In this paper we investigated the effects of Fe-doping of the anatase TiO2 (1 0 1) surface on the crystal structure, electronic and optical properties, and impurity formation energy by means of density functional theory (DFT). The calculations were performed by the SIESTA DFT code and were carried out by using Troullier-Martins pseudopotentials for the 12-electron valence configuration (3s(2)3p(6)3d(2)4s(2)) of Ti atom, 6-electron valence configuration (2s(2)p(4)) of O atom and 8-electron valence configuration (3d(6)4s(2)) of Fe atom. We used a double- zeta basis set including polarization functions. All calculations were spin-polarized. The mechanism of narrowing the band gap and increasing the photocatalytic activity in the visible light region, of the doped TiO2 is discussed by investigating the density of state. The band gap decreases as the concentration of the dopant increases. The Partial Density of States (PDOS) is not the same in the case of spin-up state or spin-down state. Enhanced optical absorption, for light polarized in the z direction (parallel to the surface normal) is clearly observed for Fe doped as compared to the pure anatase TiO2 and the optical absorption is found to increase with the increase in the Fe concentration. The DFT results indicate that the source of the increasing photocatalytic activity in the visible light region of the Fe doped material is due to the introduction of additional electronic states within the band gap. Since the Fe atoms are more stable in Ti substitutional lattice positions for the entire range of Fermi energy E-F over the band gap, only this substitutional position is considered. We hope that our results will highlight a route to improved electronic and optical properties of anatase TiO2 for industrial applications. (C) 2017 Elsevier B.V. All rights reserved.",
journal = "Computational and Theoretical Chemistry",
title = "Ab initio study of electronic and optical properties of Fe doped anatase TiO2 (101) surface",
volume = "1120",
pages = "17-23",
doi = "10.1016/j.comptc.2017.09.024"
}
Toprek, D., Koteski, V. J., Belošević-Čavor, J., Ivanovski, V. N.,& Umićević, A. (2017). Ab initio study of electronic and optical properties of Fe doped anatase TiO2 (101) surface.
Computational and Theoretical Chemistry, 1120, 17-23.
https://doi.org/10.1016/j.comptc.2017.09.024
Toprek D, Koteski VJ, Belošević-Čavor J, Ivanovski VN, Umićević A. Ab initio study of electronic and optical properties of Fe doped anatase TiO2 (101) surface. Computational and Theoretical Chemistry. 2017;1120:17-23
Toprek Dragan, Koteski Vasil J., Belošević-Čavor Jelena, Ivanovski Valentin N., Umićević Ana, "Ab initio study of electronic and optical properties of Fe doped anatase TiO2 (101) surface" Computational and Theoretical Chemistry, 1120 (2017):17-23,
https://doi.org/10.1016/j.comptc.2017.09.024 .
5
5
6

Yttrium Orthoferrite Powder Obtained by the Mechanochemical Synthesis

Lazarević, Zorica Ž.; Jovalekic, Cedomir; Gilic, Martina; Ivanovski, Valentin N.; Umićević, Ana; Sekulić, Dalibor L.; Romčević, Nebojša Ž.

(2017)

TY  - JOUR
AU  - Lazarević, Zorica Ž.
AU  - Jovalekic, Cedomir
AU  - Gilic, Martina
AU  - Ivanovski, Valentin N.
AU  - Umićević, Ana
AU  - Sekulić, Dalibor L.
AU  - Romčević, Nebojša Ž.
PY  - 2017
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1778
AB  - Yttrium orthoferrite (YFeO3) powder was prepared by a mechanochemical synthesis from a mixture of Y2O3 and alpha-Fe2O3 powders in a planetary ball mill for 2.5 h. The obtained YFeO3 powder sample was characterized by X-ray diffraction (XRD), Raman and infrared spectroscopy. The average crystallite size calculated by the Scherrer equation was 12 nm. The Mossbauer spectroscopy at room temperature confirms the superparamagnetic character of YFeO3 orthoferrite sample.
T2  - Science of Sintering
T1  - Yttrium Orthoferrite Powder Obtained by the Mechanochemical Synthesis
VL  - 49
IS  - 3
SP  - 277
EP  - 284
DO  - 10.2298/SOS1703277L
ER  - 
@article{
author = "Lazarević, Zorica Ž. and Jovalekic, Cedomir and Gilic, Martina and Ivanovski, Valentin N. and Umićević, Ana and Sekulić, Dalibor L. and Romčević, Nebojša Ž.",
year = "2017",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1778",
abstract = "Yttrium orthoferrite (YFeO3) powder was prepared by a mechanochemical synthesis from a mixture of Y2O3 and alpha-Fe2O3 powders in a planetary ball mill for 2.5 h. The obtained YFeO3 powder sample was characterized by X-ray diffraction (XRD), Raman and infrared spectroscopy. The average crystallite size calculated by the Scherrer equation was 12 nm. The Mossbauer spectroscopy at room temperature confirms the superparamagnetic character of YFeO3 orthoferrite sample.",
journal = "Science of Sintering",
title = "Yttrium Orthoferrite Powder Obtained by the Mechanochemical Synthesis",
volume = "49",
number = "3",
pages = "277-284",
doi = "10.2298/SOS1703277L"
}
Lazarević, Z. Ž., Jovalekic, C., Gilic, M., Ivanovski, V. N., Umićević, A., Sekulić, D. L.,& Romčević, N. Ž. (2017). Yttrium Orthoferrite Powder Obtained by the Mechanochemical Synthesis.
Science of Sintering, 49(3), 277-284.
https://doi.org/10.2298/SOS1703277L
Lazarević ZŽ, Jovalekic C, Gilic M, Ivanovski VN, Umićević A, Sekulić DL, Romčević NŽ. Yttrium Orthoferrite Powder Obtained by the Mechanochemical Synthesis. Science of Sintering. 2017;49(3):277-284
Lazarević Zorica Ž., Jovalekic Cedomir, Gilic Martina, Ivanovski Valentin N., Umićević Ana, Sekulić Dalibor L., Romčević Nebojša Ž., "Yttrium Orthoferrite Powder Obtained by the Mechanochemical Synthesis" Science of Sintering, 49, no. 3 (2017):277-284,
https://doi.org/10.2298/SOS1703277L .
4
5
5

First-principles calculations of tetragonal FeX (X = S, Se, Te): Magnetism, hyperfine-interaction, and bonding

Koteski, Vasil J.; Ivanovski, Valentin N.; Umićević, Ana; Belošević-Čavor, Jelena; Toprek, Dragan; Mahnke, Heinz-Eberhard

(2017)

TY  - JOUR
AU  - Koteski, Vasil J.
AU  - Ivanovski, Valentin N.
AU  - Umićević, Ana
AU  - Belošević-Čavor, Jelena
AU  - Toprek, Dragan
AU  - Mahnke, Heinz-Eberhard
PY  - 2017
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1688
AB  - Magnetic ground states, local crystallographic environment of Fe, and hyperfine interaction parameters in tetragonal FeX (X = S, Se, Te) are investigated by means of density functional theory (DFT) calculations using augmented plane waves plus local orbitals (APW + lo) method. We use several different magnetic configurations to evaluate the magnetic and electronic properties of this system, as well as the hyperfine interaction parameters at Fe lattice site. The results obtained for the ground state collinear anti-ferromagnetic arrangement relatively well reproduce the quadrupole splitting and isomer shifts from the available Mossbauer measurements. The Baders atoms in molecule charge density analysis indicates bonding of closed-shell type and a sizable charge transfer from Fe to X. The system properties are sensitive to the structural optimization of the position of the chalcogen atom with respect to the iron plane. (C) 2017 Elsevier B.V. All rights reserved.
T2  - Journal of Magnetism and Magnetic Materials
T1  - First-principles calculations of tetragonal FeX (X = S, Se, Te): Magnetism, hyperfine-interaction, and bonding
VL  - 441
SP  - 769
EP  - 775
DO  - 10.1016/j.jmmm.2017.06.092
ER  - 
@article{
author = "Koteski, Vasil J. and Ivanovski, Valentin N. and Umićević, Ana and Belošević-Čavor, Jelena and Toprek, Dragan and Mahnke, Heinz-Eberhard",
year = "2017",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1688",
abstract = "Magnetic ground states, local crystallographic environment of Fe, and hyperfine interaction parameters in tetragonal FeX (X = S, Se, Te) are investigated by means of density functional theory (DFT) calculations using augmented plane waves plus local orbitals (APW + lo) method. We use several different magnetic configurations to evaluate the magnetic and electronic properties of this system, as well as the hyperfine interaction parameters at Fe lattice site. The results obtained for the ground state collinear anti-ferromagnetic arrangement relatively well reproduce the quadrupole splitting and isomer shifts from the available Mossbauer measurements. The Baders atoms in molecule charge density analysis indicates bonding of closed-shell type and a sizable charge transfer from Fe to X. The system properties are sensitive to the structural optimization of the position of the chalcogen atom with respect to the iron plane. (C) 2017 Elsevier B.V. All rights reserved.",
journal = "Journal of Magnetism and Magnetic Materials",
title = "First-principles calculations of tetragonal FeX (X = S, Se, Te): Magnetism, hyperfine-interaction, and bonding",
volume = "441",
pages = "769-775",
doi = "10.1016/j.jmmm.2017.06.092"
}
Koteski, V. J., Ivanovski, V. N., Umićević, A., Belošević-Čavor, J., Toprek, D.,& Mahnke, H. (2017). First-principles calculations of tetragonal FeX (X = S, Se, Te): Magnetism, hyperfine-interaction, and bonding.
Journal of Magnetism and Magnetic Materials, 441, 769-775.
https://doi.org/10.1016/j.jmmm.2017.06.092
Koteski VJ, Ivanovski VN, Umićević A, Belošević-Čavor J, Toprek D, Mahnke H. First-principles calculations of tetragonal FeX (X = S, Se, Te): Magnetism, hyperfine-interaction, and bonding. Journal of Magnetism and Magnetic Materials. 2017;441:769-775
Koteski Vasil J., Ivanovski Valentin N., Umićević Ana, Belošević-Čavor Jelena, Toprek Dragan, Mahnke Heinz-Eberhard, "First-principles calculations of tetragonal FeX (X = S, Se, Te): Magnetism, hyperfine-interaction, and bonding" Journal of Magnetism and Magnetic Materials, 441 (2017):769-775,
https://doi.org/10.1016/j.jmmm.2017.06.092 .
1
1
1

Critical behavior of the van derWaals bonded ferromagnet Fe3-xGeTe2

Liu, Yu; Ivanovski, Valentin N.; Petrovic, C.

(2017)

TY  - JOUR
AU  - Liu, Yu
AU  - Ivanovski, Valentin N.
AU  - Petrovic, C.
PY  - 2017
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1795
AB  - The critical properties of the single-crystalline van der Waals bonded ferromagnet Fe3-xGeTe2 were investigated by bulk dc magnetization around the paramagnetic to ferromagnetic (FM) phase transition. The Fe3-xGeTe2 single crystals grown by self-flux method with Fe deficiency x approximate to 0.36 exhibit bulk FM ordering below T-c = 152 K. The Mossbauer spectroscopy was used to provide information on defects and local atomic environment in such crystals. Critical exponents beta = 0.372(4) with a critical temperature T-c = 151.25(5) K and gamma = 1.265(15) with T-c = 151.17(12) K are obtained by the Kouvel-Fisher method, whereas d = 4.50(1) is obtained by a critical isotherm analysis at T-c = 151 K. These critical exponents obey theWidom scaling relation delta = 1 + gamma/beta, indicating self-consistency of the obtained values. With these critical exponents the isothermM(H) curves below and above the critical temperatures collapse into two independent universal branches, obeying the single scaling equation m = f +/- (h), where m and h are renormalized magnetization and field, respectively. The exponents determined in this study are close to those calculated from the results of the renormalization group approach for a heuristic model of three-dimensional Heisenberg (d = 3, n = 3) spins coupled with the attractive long-range interactions between spins that decay as J (r) approximate to r(-(3+ sigma)) with sigma = 1.89.
T2  - Physical Review B: Condensed Matter and Materials Physics
T1  - Critical behavior of the van derWaals bonded ferromagnet Fe3-xGeTe2
VL  - 96
IS  - 14
DO  - 10.1103/PhysRevB.96.144429
ER  - 
@article{
author = "Liu, Yu and Ivanovski, Valentin N. and Petrovic, C.",
year = "2017",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1795",
abstract = "The critical properties of the single-crystalline van der Waals bonded ferromagnet Fe3-xGeTe2 were investigated by bulk dc magnetization around the paramagnetic to ferromagnetic (FM) phase transition. The Fe3-xGeTe2 single crystals grown by self-flux method with Fe deficiency x approximate to 0.36 exhibit bulk FM ordering below T-c = 152 K. The Mossbauer spectroscopy was used to provide information on defects and local atomic environment in such crystals. Critical exponents beta = 0.372(4) with a critical temperature T-c = 151.25(5) K and gamma = 1.265(15) with T-c = 151.17(12) K are obtained by the Kouvel-Fisher method, whereas d = 4.50(1) is obtained by a critical isotherm analysis at T-c = 151 K. These critical exponents obey theWidom scaling relation delta = 1 + gamma/beta, indicating self-consistency of the obtained values. With these critical exponents the isothermM(H) curves below and above the critical temperatures collapse into two independent universal branches, obeying the single scaling equation m = f +/- (h), where m and h are renormalized magnetization and field, respectively. The exponents determined in this study are close to those calculated from the results of the renormalization group approach for a heuristic model of three-dimensional Heisenberg (d = 3, n = 3) spins coupled with the attractive long-range interactions between spins that decay as J (r) approximate to r(-(3+ sigma)) with sigma = 1.89.",
journal = "Physical Review B: Condensed Matter and Materials Physics",
title = "Critical behavior of the van derWaals bonded ferromagnet Fe3-xGeTe2",
volume = "96",
number = "14",
doi = "10.1103/PhysRevB.96.144429"
}
Liu, Y., Ivanovski, V. N.,& Petrovic, C. (2017). Critical behavior of the van derWaals bonded ferromagnet Fe3-xGeTe2.
Physical Review B: Condensed Matter and Materials Physics, 96(14).
https://doi.org/10.1103/PhysRevB.96.144429
Liu Y, Ivanovski VN, Petrovic C. Critical behavior of the van derWaals bonded ferromagnet Fe3-xGeTe2. Physical Review B: Condensed Matter and Materials Physics. 2017;96(14)
Liu Yu, Ivanovski Valentin N., Petrovic C., "Critical behavior of the van derWaals bonded ferromagnet Fe3-xGeTe2" Physical Review B: Condensed Matter and Materials Physics, 96, no. 14 (2017),
https://doi.org/10.1103/PhysRevB.96.144429 .
1
29
26
29

Critical current density and vortex pinning in tetragonal FeS1-xSex (x=0,0.06)

Wang, Aifeng; Wu, Lijun; Ivanovski, Valentin N.; Warren, J. B.; Tian, Jianjun; Zhu, Yimei; Petrovic, C.

(2016)

TY  - JOUR
AU  - Wang, Aifeng
AU  - Wu, Lijun
AU  - Ivanovski, Valentin N.
AU  - Warren, J. B.
AU  - Tian, Jianjun
AU  - Zhu, Yimei
AU  - Petrovic, C.
PY  - 2016
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1232
AB  - We report critical current density (J(c)) in tetragonal FeS single crystals, similar to iron-based superconductors with much higher superconducting critical temperatures (T-c). The Jc is enhanced three times by 6% Se doping. We observe scaling of the normalized vortex pinning force as a function of reduced field at all temperatures. Vortex pinning in FeS and FeS0.94Se0.06 shows contribution of core-normal surfacelike pinning. Reduced temperature dependence of J(c) indicates that dominant interaction of vortex cores and pinning centers is via scattering of charge carriers with reduced mean free path (delta l), in contrast to KxFe2-ySe2 where spatial variations in T-c (delta T-c) prevails.
T2  - Physical Review B: Condensed Matter and Materials Physics
T1  - Critical current density and vortex pinning in tetragonal FeS1-xSex (x=0,0.06)
VL  - 94
IS  - 9
DO  - 10.1103/PhysRevB.94.094506
ER  - 
@article{
author = "Wang, Aifeng and Wu, Lijun and Ivanovski, Valentin N. and Warren, J. B. and Tian, Jianjun and Zhu, Yimei and Petrovic, C.",
year = "2016",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1232",
abstract = "We report critical current density (J(c)) in tetragonal FeS single crystals, similar to iron-based superconductors with much higher superconducting critical temperatures (T-c). The Jc is enhanced three times by 6% Se doping. We observe scaling of the normalized vortex pinning force as a function of reduced field at all temperatures. Vortex pinning in FeS and FeS0.94Se0.06 shows contribution of core-normal surfacelike pinning. Reduced temperature dependence of J(c) indicates that dominant interaction of vortex cores and pinning centers is via scattering of charge carriers with reduced mean free path (delta l), in contrast to KxFe2-ySe2 where spatial variations in T-c (delta T-c) prevails.",
journal = "Physical Review B: Condensed Matter and Materials Physics",
title = "Critical current density and vortex pinning in tetragonal FeS1-xSex (x=0,0.06)",
volume = "94",
number = "9",
doi = "10.1103/PhysRevB.94.094506"
}
Wang, A., Wu, L., Ivanovski, V. N., Warren, J. B., Tian, J., Zhu, Y.,& Petrovic, C. (2016). Critical current density and vortex pinning in tetragonal FeS1-xSex (x=0,0.06).
Physical Review B: Condensed Matter and Materials Physics, 94(9).
https://doi.org/10.1103/PhysRevB.94.094506
Wang A, Wu L, Ivanovski VN, Warren JB, Tian J, Zhu Y, Petrovic C. Critical current density and vortex pinning in tetragonal FeS1-xSex (x=0,0.06). Physical Review B: Condensed Matter and Materials Physics. 2016;94(9)
Wang Aifeng, Wu Lijun, Ivanovski Valentin N., Warren J. B., Tian Jianjun, Zhu Yimei, Petrovic C., "Critical current density and vortex pinning in tetragonal FeS1-xSex (x=0,0.06)" Physical Review B: Condensed Matter and Materials Physics, 94, no. 9 (2016),
https://doi.org/10.1103/PhysRevB.94.094506 .
1
10
12

Истраживање структуре и хиперфиних интеракција у интерметалној y'-Ni3Al фази са примесама хафнијума и гвожђа

Ivanovski, Valentin N.

(Универзитет у Београду, Физички факултет, 2015)

TY  - BOOK
AU  - Ivanovski, Valentin N.
PY  - 2015
UR  - http://eteze.bg.ac.rs/application/showtheses?thesesId=3175
UR  - https://fedorabg.bg.ac.rs/fedora/get/o:11524/bdef:Content/download
UR  - http://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=47674639
UR  - http://nardus.mpn.gov.rs/123456789/5910
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7291
AB  - У овом раду истраживана су поликристална интерметална једињења γ′–Ni3Al са примесама атома хафнијума и γ′–Ni3Al са примесама атома гвожђа. Испитивања локалне структуре, магнетних и електричних особина γ′–Ni3Al једињења допираних атомима Hf или атомима Fe извршена су методама дифракције Х–зрачења, мерењима магнетизације, као и применом временски разложених пертурбованих угаоних корелација и спектроскопије Mössbauer–овог ефекта, које су омогућиле истраживања хиперфиних интеракција на језгрима примеса Hf и на језгрима примеса Fe. Ова експериментална истраживања испитиваних система су употпуњена прорачунима енергије дефеката, као и параметара структуре и хиперфиних интеракција на основу првих принципа. Главни циљ експерименталних истраживања и теоријских прорачуна интерметалне γ′– Ni3Al фазе са примесама атома хафнијума, односно гвожђа био је да се одреди преферентно позиционирање атома Hf, односно атома Fe у γ′–Ni3Al решетки, као и њихов утицај на кристалну решетку у коју се уграђују. Aнализoм дифракције Х–зрака испитиваних Hf допираних Ni3Al узорака утврђено је присуство кубне γ′ фазе (ознака L12) у испитиваним Hf–Ni3Al легурама, као и њене две тетрагоналне трансформације L60 и D022. Анализа је показала да је кубна L12 фаза доминантна у односу на тетрагоналне фазе испитиваних Hf–Ni3Al узорака. Мерења хиперфиних интеракција на проби 181Та, језгру–потомку 181Hf, у легурама 0.2, 0.5 и 5 at.% Hf – Ni3Al извршена су у температурском опсегу од 78 K до 1230 K. Измерене вредности хиперфиних параметара приписане су одређеним позицијама атома Hf у присутним Ni3Al фазама: L12, D022 и L60. Присуствo 181Ta–сигнала који је константан у времену кореспондира атомима Hf на позицији Al атома у доминантној L12 фази. За све три испитиване легуре, измерена нижа вредност спин независне електричнеiiiквадруполне фреквенције додељена је електричној квадруполној интеракцији којадејствује на атоме Hf који су заменили атоме Al у тетрагоналној D022 фази.Измерена виша вредност фреквенције кореспондира атомима Hf на позицијамаатома Al у тетрагоналној L60 фази.Резултати прорачуна параметара хиперфиних интеракција, електронских иструктурних особина Hf–Ni3Al легура из првих принципа изведених методомпроширених равних таласа са локалним орбиталама коришћењем WIEN2k (“AnAugmented Plane Wave Plus Local Orbitals Program”) кода коректно репродукујувредности добијене у експерименталним мерењима. Прорачуни енергије дефекатабазирани на теорији функционала густине изведени су VASP (“the Vienna ab–initiosimulation package”) кодом. Прорачунате електронске структуре проба уразматрању са тачкастим групама симетрије њихових позиција помогли су уидентификовању порекла хиперфиних интеракција и утврдили да је преферентнапозиција хафнијума на позицији коју заузимају атоми Al у Ni3Al.Карактеризација узорака γ′–Ni3Al допираних гвожђем извршена једифракцијом Х–зрачења и мерењима магнетизације. Локална електронска имагнетна структура, хиперфине интеракције пробе 57Fe, као и фазни састав легураNi2.82Fe0.18Al и Ni2.64Fe0.36Al истражени су спектроскопијом Mössbauеr–овогефекта. Резултати прорачуна електронских особина Fe–Ni3Al легура из првихпринципа методом пројектора проширених таласа као и резултати прорачунаенергије дефеката објашњавају електронску структуру, хиперфине интеракције ипреферентну позицију атома Fe у легури γ′–Ni3Al са мањком никла. Вредностизрачунате највеће компоненте тензора градијента електричног поља, Vzz = 1.61021 Vm-2 на основу вредности параметара добијених из Mössbauеr–ових спектара,указује да у обе испитиване легуре атоми гвожђа замењују атоме никла у γ′–Ni3Al.
AB  - The dissertation addresses the local crystal structure and hyperfine interactions of hafnium or iron doped polycrystalline intermatallic γ′–Ni3Al alloys.The local structure, magnetic and electrical properties of γ′–Ni3Al compounds doped with Hf atoms or Fe atoms were investigated by the X ray diffraction, magnetization, time differential perturbed angular correlation spectroscopy and Mössbauer–effect spectroscopy. The last two experimental methods provided insight into hyperfine interactions of Hf– and Fe–nucleus. This was complemented by the calculations of the energy of the defects, as well as with ab initio calculations of structural and hyperfine interactions parameters.The main goal of the experimental and theoretical investigations of the intermetallic γ′–Ni3Al phase doped with Hf or Fe atoms was to determine the site preference of dopant atoms in the γ′–Ni3Al matrix, as well as their influence on the host lattice.The X–ray diffraction measurements of the Hf doped Ni3Al samples revealed the presence of the cubic γ′ phase (usually denoted by L12) and its two tetragonal distortions: D022 and L60. The refinement of XRD data showed the dominant presence of the cubic L12 phase in the Hf–Ni3Al samples, with the minority presence of the two tetragonal phases. The measurements of the hyperfine interactions of the 181Та–probe in the 0.2, 0.5 and 5 at.% Hf – Ni3Al alloys (181Та–nucleus is the daughter–nucleus of the 181Hf–parent nucleus) were done in the temperature range 78 K to 1230 K. The measured hyperfine parameters values were assigned to the various Hf atom sites in the different crystal structures (cubic and tetragonal) present in the Ni3Al alloys. The presence of 181Та–signal constant in time is ascribed to Hf atoms at the Al sites in dominant L12 phase. For all investigated alloys, the lower value of the spin independent electric quadrupole frequency was ascribed to the electric quadrupole interaction of the Hf nuclei substituting on the Al sites in the tetragonal D022 phase in the Hf–Ni3Al valloys. The higher value of the spin independent electric quadrupole frequency corresponded to the electric quadrupole interactions of the Hf nuclei substituting on the Al sites in the tetragonal L60 phase in the Hf–Ni3Al alloys.The ab initio calculations of electronic and structural properties and hyperfine parameters of the 181Ta ion probe in the Hf–Ni3Al alloys, performed using the full potential augmented plane wave plus local–orbital method as implemented in the WIEN2k code, correctly reproduce the experimental results. The DFT (density functional theory) calculations of point defect energies were done by using the Vienna ab initio simulation package VASP. The ab initio calculations enable discussion on the structural and electronic properties of the Ni3Al polycrystalline alloys.The joint experimental and theoretical investigations enabled us to identify the observed hyperfine interactions and showed that hafnium additions prefer aluminum sites in Ni3Al.The structural and magnetic characterizations of the Fe doped γ′–Ni3Al samples were done by the X–ray diffraction and magnetization measurements. The local electronic and magnetic structure, the hyperfine interactions of the 57Fe–probes, as well as the phase composition of the Ni2.82Fe0.18Al and Ni2.64Fe0.36Al alloys were investigated by means of the Mössbauer–effect spectroscopy. The ab initio calculations performed with the projector augmented wave method and the calculations of the energies of iron point defects were done to elucidate the electronic structure, the hyperfine interactions and site preference of Fe doped Ni–deficit γ′–Ni3Al. The value of calculated electric field gradient tensor Vzz = 1.6 1021 Vm-2 matches well with the results of Mössbauer spectroscopy and indicates weak preference of iron dopant atoms for Ni sites.
PB  - Универзитет у Београду, Физички факултет
T2  - Универзитет у Београду
T1  - Истраживање структуре и хиперфиних интеракција у интерметалној y'-Ni3Al фази са примесама хафнијума и гвожђа
T1  - Investigation of the structure and hyperfine interactions in the intermetallic y'-Ni3Al phase doped with hafnium and iron
ER  - 
@phdthesis{
author = "Ivanovski, Valentin N.",
year = "2015",
url = "http://eteze.bg.ac.rs/application/showtheses?thesesId=3175, https://fedorabg.bg.ac.rs/fedora/get/o:11524/bdef:Content/download, http://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=47674639, http://nardus.mpn.gov.rs/123456789/5910, http://vinar.vin.bg.ac.rs/handle/123456789/7291",
abstract = "У овом раду истраживана су поликристална интерметална једињења γ′–Ni3Al са примесама атома хафнијума и γ′–Ni3Al са примесама атома гвожђа. Испитивања локалне структуре, магнетних и електричних особина γ′–Ni3Al једињења допираних атомима Hf или атомима Fe извршена су методама дифракције Х–зрачења, мерењима магнетизације, као и применом временски разложених пертурбованих угаоних корелација и спектроскопије Mössbauer–овог ефекта, које су омогућиле истраживања хиперфиних интеракција на језгрима примеса Hf и на језгрима примеса Fe. Ова експериментална истраживања испитиваних система су употпуњена прорачунима енергије дефеката, као и параметара структуре и хиперфиних интеракција на основу првих принципа. Главни циљ експерименталних истраживања и теоријских прорачуна интерметалне γ′– Ni3Al фазе са примесама атома хафнијума, односно гвожђа био је да се одреди преферентно позиционирање атома Hf, односно атома Fe у γ′–Ni3Al решетки, као и њихов утицај на кристалну решетку у коју се уграђују. Aнализoм дифракције Х–зрака испитиваних Hf допираних Ni3Al узорака утврђено је присуство кубне γ′ фазе (ознака L12) у испитиваним Hf–Ni3Al легурама, као и њене две тетрагоналне трансформације L60 и D022. Анализа је показала да је кубна L12 фаза доминантна у односу на тетрагоналне фазе испитиваних Hf–Ni3Al узорака. Мерења хиперфиних интеракција на проби 181Та, језгру–потомку 181Hf, у легурама 0.2, 0.5 и 5 at.% Hf – Ni3Al извршена су у температурском опсегу од 78 K до 1230 K. Измерене вредности хиперфиних параметара приписане су одређеним позицијама атома Hf у присутним Ni3Al фазама: L12, D022 и L60. Присуствo 181Ta–сигнала који је константан у времену кореспондира атомима Hf на позицији Al атома у доминантној L12 фази. За све три испитиване легуре, измерена нижа вредност спин независне електричнеiiiквадруполне фреквенције додељена је електричној квадруполној интеракцији којадејствује на атоме Hf који су заменили атоме Al у тетрагоналној D022 фази.Измерена виша вредност фреквенције кореспондира атомима Hf на позицијамаатома Al у тетрагоналној L60 фази.Резултати прорачуна параметара хиперфиних интеракција, електронских иструктурних особина Hf–Ni3Al легура из првих принципа изведених методомпроширених равних таласа са локалним орбиталама коришћењем WIEN2k (“AnAugmented Plane Wave Plus Local Orbitals Program”) кода коректно репродукујувредности добијене у експерименталним мерењима. Прорачуни енергије дефекатабазирани на теорији функционала густине изведени су VASP (“the Vienna ab–initiosimulation package”) кодом. Прорачунате електронске структуре проба уразматрању са тачкастим групама симетрије њихових позиција помогли су уидентификовању порекла хиперфиних интеракција и утврдили да је преферентнапозиција хафнијума на позицији коју заузимају атоми Al у Ni3Al.Карактеризација узорака γ′–Ni3Al допираних гвожђем извршена једифракцијом Х–зрачења и мерењима магнетизације. Локална електронска имагнетна структура, хиперфине интеракције пробе 57Fe, као и фазни састав легураNi2.82Fe0.18Al и Ni2.64Fe0.36Al истражени су спектроскопијом Mössbauеr–овогефекта. Резултати прорачуна електронских особина Fe–Ni3Al легура из првихпринципа методом пројектора проширених таласа као и резултати прорачунаенергије дефеката објашњавају електронску структуру, хиперфине интеракције ипреферентну позицију атома Fe у легури γ′–Ni3Al са мањком никла. Вредностизрачунате највеће компоненте тензора градијента електричног поља, Vzz = 1.61021 Vm-2 на основу вредности параметара добијених из Mössbauеr–ових спектара,указује да у обе испитиване легуре атоми гвожђа замењују атоме никла у γ′–Ni3Al., The dissertation addresses the local crystal structure and hyperfine interactions of hafnium or iron doped polycrystalline intermatallic γ′–Ni3Al alloys.The local structure, magnetic and electrical properties of γ′–Ni3Al compounds doped with Hf atoms or Fe atoms were investigated by the X ray diffraction, magnetization, time differential perturbed angular correlation spectroscopy and Mössbauer–effect spectroscopy. The last two experimental methods provided insight into hyperfine interactions of Hf– and Fe–nucleus. This was complemented by the calculations of the energy of the defects, as well as with ab initio calculations of structural and hyperfine interactions parameters.The main goal of the experimental and theoretical investigations of the intermetallic γ′–Ni3Al phase doped with Hf or Fe atoms was to determine the site preference of dopant atoms in the γ′–Ni3Al matrix, as well as their influence on the host lattice.The X–ray diffraction measurements of the Hf doped Ni3Al samples revealed the presence of the cubic γ′ phase (usually denoted by L12) and its two tetragonal distortions: D022 and L60. The refinement of XRD data showed the dominant presence of the cubic L12 phase in the Hf–Ni3Al samples, with the minority presence of the two tetragonal phases. The measurements of the hyperfine interactions of the 181Та–probe in the 0.2, 0.5 and 5 at.% Hf – Ni3Al alloys (181Та–nucleus is the daughter–nucleus of the 181Hf–parent nucleus) were done in the temperature range 78 K to 1230 K. The measured hyperfine parameters values were assigned to the various Hf atom sites in the different crystal structures (cubic and tetragonal) present in the Ni3Al alloys. The presence of 181Та–signal constant in time is ascribed to Hf atoms at the Al sites in dominant L12 phase. For all investigated alloys, the lower value of the spin independent electric quadrupole frequency was ascribed to the electric quadrupole interaction of the Hf nuclei substituting on the Al sites in the tetragonal D022 phase in the Hf–Ni3Al valloys. The higher value of the spin independent electric quadrupole frequency corresponded to the electric quadrupole interactions of the Hf nuclei substituting on the Al sites in the tetragonal L60 phase in the Hf–Ni3Al alloys.The ab initio calculations of electronic and structural properties and hyperfine parameters of the 181Ta ion probe in the Hf–Ni3Al alloys, performed using the full potential augmented plane wave plus local–orbital method as implemented in the WIEN2k code, correctly reproduce the experimental results. The DFT (density functional theory) calculations of point defect energies were done by using the Vienna ab initio simulation package VASP. The ab initio calculations enable discussion on the structural and electronic properties of the Ni3Al polycrystalline alloys.The joint experimental and theoretical investigations enabled us to identify the observed hyperfine interactions and showed that hafnium additions prefer aluminum sites in Ni3Al.The structural and magnetic characterizations of the Fe doped γ′–Ni3Al samples were done by the X–ray diffraction and magnetization measurements. The local electronic and magnetic structure, the hyperfine interactions of the 57Fe–probes, as well as the phase composition of the Ni2.82Fe0.18Al and Ni2.64Fe0.36Al alloys were investigated by means of the Mössbauer–effect spectroscopy. The ab initio calculations performed with the projector augmented wave method and the calculations of the energies of iron point defects were done to elucidate the electronic structure, the hyperfine interactions and site preference of Fe doped Ni–deficit γ′–Ni3Al. The value of calculated electric field gradient tensor Vzz = 1.6 1021 Vm-2 matches well with the results of Mössbauer spectroscopy and indicates weak preference of iron dopant atoms for Ni sites.",
publisher = "Универзитет у Београду, Физички факултет",
journal = "Универзитет у Београду",
title = "Истраживање структуре и хиперфиних интеракција у интерметалној y'-Ni3Al фази са примесама хафнијума и гвожђа, Investigation of the structure and hyperfine interactions in the intermetallic y'-Ni3Al phase doped with hafnium and iron"
}
Ivanovski, V. N. (2015). Investigation of the structure and hyperfine interactions in the intermetallic y'-Ni3Al phase doped with hafnium and iron.
Универзитет у Београду
Универзитет у Београду, Физички факултет..
Ivanovski VN. Investigation of the structure and hyperfine interactions in the intermetallic y'-Ni3Al phase doped with hafnium and iron. Универзитет у Београду. 2015;
Ivanovski Valentin N., "Investigation of the structure and hyperfine interactions in the intermetallic y'-Ni3Al phase doped with hafnium and iron" Универзитет у Београду (2015)

Local structure study of Fe dopants in Ni-deficit Ni3Al alloys

Ivanovski, Valentin N.; Umićević, Ana; Belošević-Čavor, Jelena; Lei, Hechang; Li, Lijun; Cekić, Božidar Đ.; Koteski, Vasil J.; Petrovic, C.

(2015)

TY  - JOUR
AU  - Ivanovski, Valentin N.
AU  - Umićević, Ana
AU  - Belošević-Čavor, Jelena
AU  - Lei, Hechang
AU  - Li, Lijun
AU  - Cekić, Božidar Đ.
AU  - Koteski, Vasil J.
AU  - Petrovic, C.
PY  - 2015
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/749
AB  - The local electronic and magnetic structure, hyperfine interactions, and phase composition of polycrystalline Ni-deficient Ni3-xFexAl (x = 0.18 and 0.36) were investigated by means of Fe-57 Mossbauer spectroscopy. The samples were characterized by X-ray diffraction and magnetization measurements. The ab initio calculations performed with the projector augmented wave method and the calculations of the energies of iron point defects were done to elucidate the electronic structure and site preference of Fe doped Ni3Al. The value of calculated electric field gradient tensor V-zz = 1.6 10(21) Vm(-2) matches well with the results of Mossbauer spectroscopy and indicates that the Fe atoms occupy Ni sites. (C) 2015 Elsevier B.V. All rights reserved.
T2  - Journal of Alloys and Compounds
T1  - Local structure study of Fe dopants in Ni-deficit Ni3Al alloys
VL  - 651
SP  - 705
EP  - 711
DO  - 10.1016/j.jallcom.2015.08.171
ER  - 
@article{
author = "Ivanovski, Valentin N. and Umićević, Ana and Belošević-Čavor, Jelena and Lei, Hechang and Li, Lijun and Cekić, Božidar Đ. and Koteski, Vasil J. and Petrovic, C.",
year = "2015",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/749",
abstract = "The local electronic and magnetic structure, hyperfine interactions, and phase composition of polycrystalline Ni-deficient Ni3-xFexAl (x = 0.18 and 0.36) were investigated by means of Fe-57 Mossbauer spectroscopy. The samples were characterized by X-ray diffraction and magnetization measurements. The ab initio calculations performed with the projector augmented wave method and the calculations of the energies of iron point defects were done to elucidate the electronic structure and site preference of Fe doped Ni3Al. The value of calculated electric field gradient tensor V-zz = 1.6 10(21) Vm(-2) matches well with the results of Mossbauer spectroscopy and indicates that the Fe atoms occupy Ni sites. (C) 2015 Elsevier B.V. All rights reserved.",
journal = "Journal of Alloys and Compounds",
title = "Local structure study of Fe dopants in Ni-deficit Ni3Al alloys",
volume = "651",
pages = "705-711",
doi = "10.1016/j.jallcom.2015.08.171"
}
Ivanovski, V. N., Umićević, A., Belošević-Čavor, J., Lei, H., Li, L., Cekić, B. Đ., Koteski, V. J.,& Petrovic, C. (2015). Local structure study of Fe dopants in Ni-deficit Ni3Al alloys.
Journal of Alloys and Compounds, 651, 705-711.
https://doi.org/10.1016/j.jallcom.2015.08.171
Ivanovski VN, Umićević A, Belošević-Čavor J, Lei H, Li L, Cekić BĐ, Koteski VJ, Petrovic C. Local structure study of Fe dopants in Ni-deficit Ni3Al alloys. Journal of Alloys and Compounds. 2015;651:705-711
Ivanovski Valentin N., Umićević Ana, Belošević-Čavor Jelena, Lei Hechang, Li Lijun, Cekić Božidar Đ., Koteski Vasil J., Petrovic C., "Local structure study of Fe dopants in Ni-deficit Ni3Al alloys" Journal of Alloys and Compounds, 651 (2015):705-711,
https://doi.org/10.1016/j.jallcom.2015.08.171 .
3
4
4

Site preference of Hf dopant in Ni3Al alloys: A perturbed angular correlation study

Ivanovski, Valentin N.; Cekić, Božidar Đ.; Umićević, Ana; Barudžija, Tanja; Schumacher, G.; Mađarević, Ivan; Koteski, Vasil J.

(2015)

TY  - JOUR
AU  - Ivanovski, Valentin N.
AU  - Cekić, Božidar Đ.
AU  - Umićević, Ana
AU  - Barudžija, Tanja
AU  - Schumacher, G.
AU  - Mađarević, Ivan
AU  - Koteski, Vasil J.
PY  - 2015
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/249
AB  - Perturbed angular correlation measurements of the hyperfine interactions of the Ta-181 probe in the polycrystalline intermetallic Ni3Al doped with 0.5 and 5 at.% Hf were performed in the temperature range 78-1230 K. The observed local hyperfine fields at the Hf-181/Ta-181 probe showed that Hf atoms are substituting on Al sites in the L1(2) structure of Ni3Al. The two minor electric quadrupole interactions that were found for each Ni3Al alloy are discussed taking into account the L1(2) cubic structure and its two tetragonal distortions: D0(22) and L6(0). The presence of two tetragonal transformations of the parent cubic L1(2) lattice in 0.5 at.% Hf and 5 at.% Hf doped Ni3Al was revealed by X-ray diffraction. The ab initio calculations, performed with the projector augmented wave method correctly reproduce the experimental results and enable discussion on the structural and electronic properties of the polycrystalline alloys. The experimental and theoretical investigations showed that hafnium additions prefer aluminum sites in Ni3Al. (C) 2014 Elsevier B.V. All rights reserved.
T2  - Journal of Alloys and Compounds
T1  - Site preference of Hf dopant in Ni3Al alloys: A perturbed angular correlation study
VL  - 622
SP  - 541
EP  - 547
DO  - 10.1016/j.jallcom.2014.10.132
ER  - 
@article{
author = "Ivanovski, Valentin N. and Cekić, Božidar Đ. and Umićević, Ana and Barudžija, Tanja and Schumacher, G. and Mađarević, Ivan and Koteski, Vasil J.",
year = "2015",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/249",
abstract = "Perturbed angular correlation measurements of the hyperfine interactions of the Ta-181 probe in the polycrystalline intermetallic Ni3Al doped with 0.5 and 5 at.% Hf were performed in the temperature range 78-1230 K. The observed local hyperfine fields at the Hf-181/Ta-181 probe showed that Hf atoms are substituting on Al sites in the L1(2) structure of Ni3Al. The two minor electric quadrupole interactions that were found for each Ni3Al alloy are discussed taking into account the L1(2) cubic structure and its two tetragonal distortions: D0(22) and L6(0). The presence of two tetragonal transformations of the parent cubic L1(2) lattice in 0.5 at.% Hf and 5 at.% Hf doped Ni3Al was revealed by X-ray diffraction. The ab initio calculations, performed with the projector augmented wave method correctly reproduce the experimental results and enable discussion on the structural and electronic properties of the polycrystalline alloys. The experimental and theoretical investigations showed that hafnium additions prefer aluminum sites in Ni3Al. (C) 2014 Elsevier B.V. All rights reserved.",
journal = "Journal of Alloys and Compounds",
title = "Site preference of Hf dopant in Ni3Al alloys: A perturbed angular correlation study",
volume = "622",
pages = "541-547",
doi = "10.1016/j.jallcom.2014.10.132"
}
Ivanovski, V. N., Cekić, B. Đ., Umićević, A., Barudžija, T., Schumacher, G., Mađarević, I.,& Koteski, V. J. (2015). Site preference of Hf dopant in Ni3Al alloys: A perturbed angular correlation study.
Journal of Alloys and Compounds, 622, 541-547.
https://doi.org/10.1016/j.jallcom.2014.10.132
Ivanovski VN, Cekić BĐ, Umićević A, Barudžija T, Schumacher G, Mađarević I, Koteski VJ. Site preference of Hf dopant in Ni3Al alloys: A perturbed angular correlation study. Journal of Alloys and Compounds. 2015;622:541-547
Ivanovski Valentin N., Cekić Božidar Đ., Umićević Ana, Barudžija Tanja, Schumacher G., Mađarević Ivan, Koteski Vasil J., "Site preference of Hf dopant in Ni3Al alloys: A perturbed angular correlation study" Journal of Alloys and Compounds, 622 (2015):541-547,
https://doi.org/10.1016/j.jallcom.2014.10.132 .
3
3
3

Spectroscopy investigation of nanostructured nickel-zinc ferrite obtained by mechanochemical synthesis

Lazarević, Zorica Ž.; Milutinovic, Aleksandra N.; Jovalekic, Cedomir D.; Ivanovski, Valentin N.; Daneu, Nina; Mađarević, Ivan; Romčević, Nebojša Ž.

(2015)

TY  - JOUR
AU  - Lazarević, Zorica Ž.
AU  - Milutinovic, Aleksandra N.
AU  - Jovalekic, Cedomir D.
AU  - Ivanovski, Valentin N.
AU  - Daneu, Nina
AU  - Mađarević, Ivan
AU  - Romčević, Nebojša Ž.
PY  - 2015
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/386
AB  - Nano crystalline samples of nickel zinc ferrite, Ni0.5Zn0.5Fe2O4 were prepared by mechanochemical route in a planetary ball mill starting from two mixtures of the appropriate quantities of the powders: case (1) oxide powders: NiO, ZnO and alpha-Fe2O3 in one case, and in the second case (2) hydroxide powders: Ni(OH)(2), Zn(OH)(2) and Fe(OH)(3). In order to monitor the progress of chemical reaction and confirm phase formation, powder samples obtained after 5 h and 10 h of milling were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman, IR and Mossbauer spectroscopy. It is shown that the soft mechanochemical method, i.e. mechanochemical activation of hydroxides, produces high quality single phase Ni0.5Zn0.5Fe2O4 samples in much more efficient way. From the IR spectroscopy of single phase samples it is obvious that energy of modes depends on the ratio of cations. The deconvolution of Raman spectra allows to separate contributions of different cations to a particular type of vibration and to estimate the degree of inversion. (C) 2014 Elsevier Ltd. All rights reserved.
T2  - Materials Research Bulletin
T1  - Spectroscopy investigation of nanostructured nickel-zinc ferrite obtained by mechanochemical synthesis
VL  - 63
SP  - 239
EP  - 247
DO  - 10.1016/j.materresbull.2014.12.005
ER  - 
@article{
author = "Lazarević, Zorica Ž. and Milutinovic, Aleksandra N. and Jovalekic, Cedomir D. and Ivanovski, Valentin N. and Daneu, Nina and Mađarević, Ivan and Romčević, Nebojša Ž.",
year = "2015",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/386",
abstract = "Nano crystalline samples of nickel zinc ferrite, Ni0.5Zn0.5Fe2O4 were prepared by mechanochemical route in a planetary ball mill starting from two mixtures of the appropriate quantities of the powders: case (1) oxide powders: NiO, ZnO and alpha-Fe2O3 in one case, and in the second case (2) hydroxide powders: Ni(OH)(2), Zn(OH)(2) and Fe(OH)(3). In order to monitor the progress of chemical reaction and confirm phase formation, powder samples obtained after 5 h and 10 h of milling were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman, IR and Mossbauer spectroscopy. It is shown that the soft mechanochemical method, i.e. mechanochemical activation of hydroxides, produces high quality single phase Ni0.5Zn0.5Fe2O4 samples in much more efficient way. From the IR spectroscopy of single phase samples it is obvious that energy of modes depends on the ratio of cations. The deconvolution of Raman spectra allows to separate contributions of different cations to a particular type of vibration and to estimate the degree of inversion. (C) 2014 Elsevier Ltd. All rights reserved.",
journal = "Materials Research Bulletin",
title = "Spectroscopy investigation of nanostructured nickel-zinc ferrite obtained by mechanochemical synthesis",
volume = "63",
pages = "239-247",
doi = "10.1016/j.materresbull.2014.12.005"
}
Lazarević, Z. Ž., Milutinovic, A. N., Jovalekic, C. D., Ivanovski, V. N., Daneu, N., Mađarević, I.,& Romčević, N. Ž. (2015). Spectroscopy investigation of nanostructured nickel-zinc ferrite obtained by mechanochemical synthesis.
Materials Research Bulletin, 63, 239-247.
https://doi.org/10.1016/j.materresbull.2014.12.005
Lazarević ZŽ, Milutinovic AN, Jovalekic CD, Ivanovski VN, Daneu N, Mađarević I, Romčević NŽ. Spectroscopy investigation of nanostructured nickel-zinc ferrite obtained by mechanochemical synthesis. Materials Research Bulletin. 2015;63:239-247
Lazarević Zorica Ž., Milutinovic Aleksandra N., Jovalekic Cedomir D., Ivanovski Valentin N., Daneu Nina, Mađarević Ivan, Romčević Nebojša Ž., "Spectroscopy investigation of nanostructured nickel-zinc ferrite obtained by mechanochemical synthesis" Materials Research Bulletin, 63 (2015):239-247,
https://doi.org/10.1016/j.materresbull.2014.12.005 .
13
9
11

Characterization of partially inverse spinel ZnFe2O4 with high saturation magnetization synthesized via soft mechanochemically assisted route

Lazarević, Zorica Ž.; Jovalekic, Cedomir; Ivanovski, Valentin N.; Recnik, Aleksander; Milutinovic, Aleksandra; Cekić, Božidar Đ.; Romčević, Nebojša Ž.

(2014)

TY  - JOUR
AU  - Lazarević, Zorica Ž.
AU  - Jovalekic, Cedomir
AU  - Ivanovski, Valentin N.
AU  - Recnik, Aleksander
AU  - Milutinovic, Aleksandra
AU  - Cekić, Božidar Đ.
AU  - Romčević, Nebojša Ž.
PY  - 2014
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/6009
AB  - ZnFe2O4 was prepared by a soft mechanochemical route from two starting combinations of powders: (1) Zn(OH)(2)/alpha-Fe2O3 and (2) Zn(OH)(2)/Fe(OH)(3) mixed in a planetary ball mill. The mechanochemical treatment provoked reaction leading to the formation of the ZnFe2O4 spinel phase that was monitored by XRD, TEM, IR and Raman spectroscopy. The spinel phase was first observed after 4 h of milling and its formation was completed after 18 h in both the cases of starting precursors. The synthesized ZnFe2O4 has a nanocrystalline structure with a crystallite size of about 20.3 and 17.6 nm, for the cases (1) and (2), respectively. In the far-infrared reflectivity spectra are seen four active modes. Raman spectra suggest an existence of mixed spinel structure in the obtained nanosamples. In order to confirm phase formation and cation arrangement, Mossbauer measurements were done. Estimated degree of inversion is about 0.58 for both starting mixtures. The magnetic properties of the prepared ZnFe2O4 powders were also studied. The results show that the samples have a typical superparamagnetic-like behavior at room temperature. Higher values of magnetization in the case of samples obtained with starting mixture (2) suggest somewhat higher degree of cation inversion. (C) 2014 Elsevier Ltd. All rights reserved.
T2  - Journal of Physics and Chemistry of Solids
T1  - Characterization of partially inverse spinel ZnFe2O4 with high saturation magnetization synthesized via soft mechanochemically assisted route
VL  - 75
IS  - 7
SP  - 869
EP  - 877
DO  - 10.1016/j.jpcs.2014.03.004
ER  - 
@article{
author = "Lazarević, Zorica Ž. and Jovalekic, Cedomir and Ivanovski, Valentin N. and Recnik, Aleksander and Milutinovic, Aleksandra and Cekić, Božidar Đ. and Romčević, Nebojša Ž.",
year = "2014",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/6009",
abstract = "ZnFe2O4 was prepared by a soft mechanochemical route from two starting combinations of powders: (1) Zn(OH)(2)/alpha-Fe2O3 and (2) Zn(OH)(2)/Fe(OH)(3) mixed in a planetary ball mill. The mechanochemical treatment provoked reaction leading to the formation of the ZnFe2O4 spinel phase that was monitored by XRD, TEM, IR and Raman spectroscopy. The spinel phase was first observed after 4 h of milling and its formation was completed after 18 h in both the cases of starting precursors. The synthesized ZnFe2O4 has a nanocrystalline structure with a crystallite size of about 20.3 and 17.6 nm, for the cases (1) and (2), respectively. In the far-infrared reflectivity spectra are seen four active modes. Raman spectra suggest an existence of mixed spinel structure in the obtained nanosamples. In order to confirm phase formation and cation arrangement, Mossbauer measurements were done. Estimated degree of inversion is about 0.58 for both starting mixtures. The magnetic properties of the prepared ZnFe2O4 powders were also studied. The results show that the samples have a typical superparamagnetic-like behavior at room temperature. Higher values of magnetization in the case of samples obtained with starting mixture (2) suggest somewhat higher degree of cation inversion. (C) 2014 Elsevier Ltd. All rights reserved.",
journal = "Journal of Physics and Chemistry of Solids",
title = "Characterization of partially inverse spinel ZnFe2O4 with high saturation magnetization synthesized via soft mechanochemically assisted route",
volume = "75",
number = "7",
pages = "869-877",
doi = "10.1016/j.jpcs.2014.03.004"
}
Lazarević, Z. Ž., Jovalekic, C., Ivanovski, V. N., Recnik, A., Milutinovic, A., Cekić, B. Đ.,& Romčević, N. Ž. (2014). Characterization of partially inverse spinel ZnFe2O4 with high saturation magnetization synthesized via soft mechanochemically assisted route.
Journal of Physics and Chemistry of Solids, 75(7), 869-877.
https://doi.org/10.1016/j.jpcs.2014.03.004
Lazarević ZŽ, Jovalekic C, Ivanovski VN, Recnik A, Milutinovic A, Cekić BĐ, Romčević NŽ. Characterization of partially inverse spinel ZnFe2O4 with high saturation magnetization synthesized via soft mechanochemically assisted route. Journal of Physics and Chemistry of Solids. 2014;75(7):869-877
Lazarević Zorica Ž., Jovalekic Cedomir, Ivanovski Valentin N., Recnik Aleksander, Milutinovic Aleksandra, Cekić Božidar Đ., Romčević Nebojša Ž., "Characterization of partially inverse spinel ZnFe2O4 with high saturation magnetization synthesized via soft mechanochemically assisted route" Journal of Physics and Chemistry of Solids, 75, no. 7 (2014):869-877,
https://doi.org/10.1016/j.jpcs.2014.03.004 .
30
31
30

Li2FeSiO4 cathode material: the structure and electrochemical performances

Jugović, Dragana; Milović, Miloš; Mitrić, Miodrag; Ivanovski, Valentin N.; Avdeev, Max; Jokić, Bojan M.; Dominko, Robert; Uskoković, Dragan

(Belgrade : Materials Research Society of Serbia, 2014)

TY  - CONF
AU  - Jugović, Dragana
AU  - Milović, Miloš
AU  - Mitrić, Miodrag
AU  - Ivanovski, Valentin N.
AU  - Avdeev, Max
AU  - Jokić, Bojan M.
AU  - Dominko, Robert
AU  - Uskoković, Dragan
PY  - 2014
UR  - http://dais.sanu.ac.rs/123456789/590
UR  - http://www.itn.sanu.ac.rs/opus4/frontdoor/index/index/docId/859
UR  - http://www.itn.sanu.ac.rs/opus4/files/859/Jugovic_YUCOMAT2014.pdf
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7487
AB  - Monoclinic Li2FeSiO4 that crystallizes in P21/n space group was investigated as a potential cathode material for lithium-ion batteries. A combined X-ray diffraction and Mössbauer spectroscopy study was used for the structural investigation. It was found that the crystal structure is prone to an “antisite” defect, the one in which the Fe ion and the Li ion exchange places. This finding was also confirmed by the Mössbauer spectroscopy. In order to obtain composites of Li2FeSiO4 and carbon, several synthesis techniques that use different carbon sources were involved. Electrochemical performances were investigated through galvanostatic charge/discharge tests. Discharge curve profile did not reflect a two-phase intercalation reaction (no obvious voltage plateau) due to the low conductivity at room temperature.
PB  - Belgrade : Materials Research Society of Serbia
C3  - The Sixteenth Annual Conference YUCOMAT 2014: Programme and the Book of Abstracts
T1  - Li2FeSiO4 cathode material: the structure and electrochemical performances
SP  - 6
EP  - 6
ER  - 
@conference{
author = "Jugović, Dragana and Milović, Miloš and Mitrić, Miodrag and Ivanovski, Valentin N. and Avdeev, Max and Jokić, Bojan M. and Dominko, Robert and Uskoković, Dragan",
year = "2014",
url = "http://dais.sanu.ac.rs/123456789/590, http://www.itn.sanu.ac.rs/opus4/frontdoor/index/index/docId/859, http://www.itn.sanu.ac.rs/opus4/files/859/Jugovic_YUCOMAT2014.pdf, http://vinar.vin.bg.ac.rs/handle/123456789/7487",
abstract = "Monoclinic Li2FeSiO4 that crystallizes in P21/n space group was investigated as a potential cathode material for lithium-ion batteries. A combined X-ray diffraction and Mössbauer spectroscopy study was used for the structural investigation. It was found that the crystal structure is prone to an “antisite” defect, the one in which the Fe ion and the Li ion exchange places. This finding was also confirmed by the Mössbauer spectroscopy. In order to obtain composites of Li2FeSiO4 and carbon, several synthesis techniques that use different carbon sources were involved. Electrochemical performances were investigated through galvanostatic charge/discharge tests. Discharge curve profile did not reflect a two-phase intercalation reaction (no obvious voltage plateau) due to the low conductivity at room temperature.",
publisher = "Belgrade : Materials Research Society of Serbia",
journal = "The Sixteenth Annual Conference YUCOMAT 2014: Programme and the Book of Abstracts",
title = "Li2FeSiO4 cathode material: the structure and electrochemical performances",
pages = "6-6"
}
Jugović, D., Milović, M., Mitrić, M., Ivanovski, V. N., Avdeev, M., Jokić, B. M., Dominko, R.,& Uskoković, D. (2014). Li2FeSiO4 cathode material: the structure and electrochemical performances.
The Sixteenth Annual Conference YUCOMAT 2014: Programme and the Book of Abstracts
Belgrade : Materials Research Society of Serbia., 6-6.
Jugović D, Milović M, Mitrić M, Ivanovski VN, Avdeev M, Jokić BM, Dominko R, Uskoković D. Li2FeSiO4 cathode material: the structure and electrochemical performances. The Sixteenth Annual Conference YUCOMAT 2014: Programme and the Book of Abstracts. 2014;:6-6
Jugović Dragana, Milović Miloš, Mitrić Miodrag, Ivanovski Valentin N., Avdeev Max, Jokić Bojan M., Dominko Robert, Uskoković Dragan, "Li2FeSiO4 cathode material: the structure and electrochemical performances" The Sixteenth Annual Conference YUCOMAT 2014: Programme and the Book of Abstracts (2014):6-6

Structural study of monoclinic Li2FeSiO4 by X-ray diffraction and Mossbauer spectroscopy

Jugović, Dragana; Milović, Miloš; Ivanovski, Valentin N.; Avdeev, Max; Dominko, Robert; Jokić, Bojan M.; Uskoković, Dragan

(2014)

TY  - JOUR
AU  - Jugović, Dragana
AU  - Milović, Miloš
AU  - Ivanovski, Valentin N.
AU  - Avdeev, Max
AU  - Dominko, Robert
AU  - Jokić, Bojan M.
AU  - Uskoković, Dragan
PY  - 2014
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/6045
AB  - A composite powder Li2FeSiO4/C is synthesized through a solid state reaction at 750 C. The Rietveld crystal structure refinement is done in the monoclinic P2(1)/n space group. It is found that the crystal structure is prone to antisite defect where small part of iron ion occupies exclusively Li(2) crystallographic position, of two different lithium tetrahedral positions (Li(1) and Li(2)). This finding is also confirmed by Mossbauer spectroscopy study: the sextet evidenced in the Mossbauer spectrum is assigned to the iron ions positioned at the Li(2) sites. A bond-valence energy landscape calculation is used to predict the conduction pathways of lithium ions. The calculations suggest that Li conductivity is two-dimensional in the (101) plane. Upon galvanostatic cyclings the structure starts to rearrange to inverse,311 polymorph. (C) 2014 Elsevier B.V. All rights reserved.
T2  - Journal of Power Sources
T1  - Structural study of monoclinic Li2FeSiO4 by X-ray diffraction and Mossbauer spectroscopy
VL  - 265
SP  - 75
EP  - 80
DO  - 10.1016/j.jpowsour.2014.04.121
ER  - 
@article{
author = "Jugović, Dragana and Milović, Miloš and Ivanovski, Valentin N. and Avdeev, Max and Dominko, Robert and Jokić, Bojan M. and Uskoković, Dragan",
year = "2014",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/6045",
abstract = "A composite powder Li2FeSiO4/C is synthesized through a solid state reaction at 750 C. The Rietveld crystal structure refinement is done in the monoclinic P2(1)/n space group. It is found that the crystal structure is prone to antisite defect where small part of iron ion occupies exclusively Li(2) crystallographic position, of two different lithium tetrahedral positions (Li(1) and Li(2)). This finding is also confirmed by Mossbauer spectroscopy study: the sextet evidenced in the Mossbauer spectrum is assigned to the iron ions positioned at the Li(2) sites. A bond-valence energy landscape calculation is used to predict the conduction pathways of lithium ions. The calculations suggest that Li conductivity is two-dimensional in the (101) plane. Upon galvanostatic cyclings the structure starts to rearrange to inverse,311 polymorph. (C) 2014 Elsevier B.V. All rights reserved.",
journal = "Journal of Power Sources",
title = "Structural study of monoclinic Li2FeSiO4 by X-ray diffraction and Mossbauer spectroscopy",
volume = "265",
pages = "75-80",
doi = "10.1016/j.jpowsour.2014.04.121"
}
Jugović, D., Milović, M., Ivanovski, V. N., Avdeev, M., Dominko, R., Jokić, B. M.,& Uskoković, D. (2014). Structural study of monoclinic Li2FeSiO4 by X-ray diffraction and Mossbauer spectroscopy.
Journal of Power Sources, 265, 75-80.
https://doi.org/10.1016/j.jpowsour.2014.04.121
Jugović D, Milović M, Ivanovski VN, Avdeev M, Dominko R, Jokić BM, Uskoković D. Structural study of monoclinic Li2FeSiO4 by X-ray diffraction and Mossbauer spectroscopy. Journal of Power Sources. 2014;265:75-80
Jugović Dragana, Milović Miloš, Ivanovski Valentin N., Avdeev Max, Dominko Robert, Jokić Bojan M., Uskoković Dragan, "Structural study of monoclinic Li2FeSiO4 by X-ray diffraction and Mossbauer spectroscopy" Journal of Power Sources, 265 (2014):75-80,
https://doi.org/10.1016/j.jpowsour.2014.04.121 .
10
11
13

Preparation and characterization of spinel nickel ferrite obtained by the soft mechanochemically assisted synthesis

Lazarević, Zorica Ž.; Jovalekic, C.; Recnik, A.; Ivanovski, Valentin N.; Milutinovic, A.; Romčević, Maja J.; Pavlović, Miodrag B.; Cekić, Božidar Đ.; Romčević, Nebojša Ž.

(2013)

TY  - JOUR
AU  - Lazarević, Zorica Ž.
AU  - Jovalekic, C.
AU  - Recnik, A.
AU  - Ivanovski, Valentin N.
AU  - Milutinovic, A.
AU  - Romčević, Maja J.
AU  - Pavlović, Miodrag B.
AU  - Cekić, Božidar Đ.
AU  - Romčević, Nebojša Ž.
PY  - 2013
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/5357
AB  - Nickel ferrite, NiFe2O4 has been prepared by a soft mechanochemical route from mixture of (1) Ni(OH)(2) and alpha-Fe2O3 and (2) Ni(OH)(2) and Fe(OH)(3) powders in a planetary ball mill for varying duration. Soft mechanochemical reaction leading to formation of the NiFe2O4 spinel phase was followed by X-ray diffraction, Raman and infrared spectroscopy, TGA, scanning and transmission microscopy. The spinel phase formation was first observed after 4 h of milling and its formation was completed after 25 h in the both cases. The synthesized NiFe2O4 ferrite has a nanocrystalline structure with a crystallite size of about 20 and 10 nm respectively for the cases (1) and (2). The final grain size in the system (1) is about twice as large as that in the system (2), what is a consequence of different reaction paths in these two processing routes. There are five Raman and four IR active modes. Mossbauer spectroscopy studies implied on the possible cation distribution between the tetrahedral and octahedral sites in formed NiFe2O4 spinel structure. We were able to estimate the degree of inversion at most 0.82 in the case (1) and 0.66 in the case (2). (c) 2012 Elsevier Ltd. All rights reserved.
T2  - Materials Research Bulletin
T1  - Preparation and characterization of spinel nickel ferrite obtained by the soft mechanochemically assisted synthesis
VL  - 48
IS  - 2
SP  - 404
EP  - 415
DO  - 10.1016/j.materresbull.2012.10.061
ER  - 
@article{
author = "Lazarević, Zorica Ž. and Jovalekic, C. and Recnik, A. and Ivanovski, Valentin N. and Milutinovic, A. and Romčević, Maja J. and Pavlović, Miodrag B. and Cekić, Božidar Đ. and Romčević, Nebojša Ž.",
year = "2013",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/5357",
abstract = "Nickel ferrite, NiFe2O4 has been prepared by a soft mechanochemical route from mixture of (1) Ni(OH)(2) and alpha-Fe2O3 and (2) Ni(OH)(2) and Fe(OH)(3) powders in a planetary ball mill for varying duration. Soft mechanochemical reaction leading to formation of the NiFe2O4 spinel phase was followed by X-ray diffraction, Raman and infrared spectroscopy, TGA, scanning and transmission microscopy. The spinel phase formation was first observed after 4 h of milling and its formation was completed after 25 h in the both cases. The synthesized NiFe2O4 ferrite has a nanocrystalline structure with a crystallite size of about 20 and 10 nm respectively for the cases (1) and (2). The final grain size in the system (1) is about twice as large as that in the system (2), what is a consequence of different reaction paths in these two processing routes. There are five Raman and four IR active modes. Mossbauer spectroscopy studies implied on the possible cation distribution between the tetrahedral and octahedral sites in formed NiFe2O4 spinel structure. We were able to estimate the degree of inversion at most 0.82 in the case (1) and 0.66 in the case (2). (c) 2012 Elsevier Ltd. All rights reserved.",
journal = "Materials Research Bulletin",
title = "Preparation and characterization of spinel nickel ferrite obtained by the soft mechanochemically assisted synthesis",
volume = "48",
number = "2",
pages = "404-415",
doi = "10.1016/j.materresbull.2012.10.061"
}
Lazarević, Z. Ž., Jovalekic, C., Recnik, A., Ivanovski, V. N., Milutinovic, A., Romčević, M. J., Pavlović, M. B., Cekić, B. Đ.,& Romčević, N. Ž. (2013). Preparation and characterization of spinel nickel ferrite obtained by the soft mechanochemically assisted synthesis.
Materials Research Bulletin, 48(2), 404-415.
https://doi.org/10.1016/j.materresbull.2012.10.061
Lazarević ZŽ, Jovalekic C, Recnik A, Ivanovski VN, Milutinovic A, Romčević MJ, Pavlović MB, Cekić BĐ, Romčević NŽ. Preparation and characterization of spinel nickel ferrite obtained by the soft mechanochemically assisted synthesis. Materials Research Bulletin. 2013;48(2):404-415
Lazarević Zorica Ž., Jovalekic C., Recnik A., Ivanovski Valentin N., Milutinovic A., Romčević Maja J., Pavlović Miodrag B., Cekić Božidar Đ., Romčević Nebojša Ž., "Preparation and characterization of spinel nickel ferrite obtained by the soft mechanochemically assisted synthesis" Materials Research Bulletin, 48, no. 2 (2013):404-415,
https://doi.org/10.1016/j.materresbull.2012.10.061 .
23
25
27

Nanodimensional spinel NiFe2O4 and ZnFe2O4 ferrites prepared by soft mechanochemical synthesis

Lazarević, Zorica Ž.; Jovalekic, C.; Milutinovic, A.; Sekulić, Dalibor L.; Ivanovski, Valentin N.; Recnik, A.; Cekić, Božidar Đ.; Romčević, Nebojša Ž.

(2013)

TY  - JOUR
AU  - Lazarević, Zorica Ž.
AU  - Jovalekic, C.
AU  - Milutinovic, A.
AU  - Sekulić, Dalibor L.
AU  - Ivanovski, Valentin N.
AU  - Recnik, A.
AU  - Cekić, Božidar Đ.
AU  - Romčević, Nebojša Ž.
PY  - 2013
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/7003
AB  - NiFe2O4 and ZnFe2O4 ferrites have been prepared by soft mechanochemical synthesis. The formation of spinel phase and crystal structure of sintered powders were analyzed by X-ray diffraction, Raman spectroscopy, and transmission microscopy. In order to confirm phase formation and cation arrangement, Mossbauer measurements were done. Investigation of the magnetization as a function of magnetic field confirms an expected change of the degree of inversion in the spinel structure with the sintering. The electrical DC/resistivity/conductivity was measured in the temperature range of 298-423 K. Impedance spectroscopy was performed in the wide frequency range (100 Hz-10 MHz) at different temperatures. (C) 2 013 AIP Publishing LLC
T2  - Journal of Applied Physics
T1  - Nanodimensional spinel NiFe2O4 and ZnFe2O4 ferrites prepared by soft mechanochemical synthesis
VL  - 113
IS  - 18
DO  - 10.1063/1.4801962
ER  - 
@article{
author = "Lazarević, Zorica Ž. and Jovalekic, C. and Milutinovic, A. and Sekulić, Dalibor L. and Ivanovski, Valentin N. and Recnik, A. and Cekić, Božidar Đ. and Romčević, Nebojša Ž.",
year = "2013",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/7003",
abstract = "NiFe2O4 and ZnFe2O4 ferrites have been prepared by soft mechanochemical synthesis. The formation of spinel phase and crystal structure of sintered powders were analyzed by X-ray diffraction, Raman spectroscopy, and transmission microscopy. In order to confirm phase formation and cation arrangement, Mossbauer measurements were done. Investigation of the magnetization as a function of magnetic field confirms an expected change of the degree of inversion in the spinel structure with the sintering. The electrical DC/resistivity/conductivity was measured in the temperature range of 298-423 K. Impedance spectroscopy was performed in the wide frequency range (100 Hz-10 MHz) at different temperatures. (C) 2 013 AIP Publishing LLC",
journal = "Journal of Applied Physics",
title = "Nanodimensional spinel NiFe2O4 and ZnFe2O4 ferrites prepared by soft mechanochemical synthesis",
volume = "113",
number = "18",
doi = "10.1063/1.4801962"
}
Lazarević, Z. Ž., Jovalekic, C., Milutinovic, A., Sekulić, D. L., Ivanovski, V. N., Recnik, A., Cekić, B. Đ.,& Romčević, N. Ž. (2013). Nanodimensional spinel NiFe2O4 and ZnFe2O4 ferrites prepared by soft mechanochemical synthesis.
Journal of Applied Physics, 113(18).
https://doi.org/10.1063/1.4801962
Lazarević ZŽ, Jovalekic C, Milutinovic A, Sekulić DL, Ivanovski VN, Recnik A, Cekić BĐ, Romčević NŽ. Nanodimensional spinel NiFe2O4 and ZnFe2O4 ferrites prepared by soft mechanochemical synthesis. Journal of Applied Physics. 2013;113(18)
Lazarević Zorica Ž., Jovalekic C., Milutinovic A., Sekulić Dalibor L., Ivanovski Valentin N., Recnik A., Cekić Božidar Đ., Romčević Nebojša Ž., "Nanodimensional spinel NiFe2O4 and ZnFe2O4 ferrites prepared by soft mechanochemical synthesis" Journal of Applied Physics, 113, no. 18 (2013),
https://doi.org/10.1063/1.4801962 .
83
79
87

Hf dopants in gamma -Ni3Al alloy

Ivanovski, Valentin N.; Cekić, Božidar Đ.; Umićević, Ana; Belošević-Čavor, Jelena; Schumacher, G.; Koteski, Vasil J.; Barudžija, Tanja

(2013)

TY  - JOUR
AU  - Ivanovski, Valentin N.
AU  - Cekić, Božidar Đ.
AU  - Umićević, Ana
AU  - Belošević-Čavor, Jelena
AU  - Schumacher, G.
AU  - Koteski, Vasil J.
AU  - Barudžija, Tanja
PY  - 2013
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/5625
AB  - The Time Differential Perturbed Angular (TDPAC) measurements of nuclear quadrupole interactions (NQIs) at Ta-181 ion probe in the polycrystalline intermetallic alloy gamma-Ni3Al doped with 0.2 at. % Hf were performed in the temperature range 78-1230K, in order to determine the lattice location of Hf atoms in the ordered gamma-Ni3Al structure. The two NQIs obtained are discussed within the present L1(2) cubic structure and a tetragonal distortion of L1(2) to another two DO22 and L6(0) type structures. The first low frequency NQI at the site of the Ta-181 ion-probe after substitution of aluminum for hafnium in DO22 at ambient temperature, is v(Q1)(300 K) = 39(1) MHz with eta(1) = 0. The corresponding high frequency value on the second crystallographic site in L6(0), is v(Q2)(300 K) = 204(14) MHz with eta(2) = 0.47(11). These two NQIs have different temperature behavior. The presence of both DO22 and L6(0) tetragonal distortions of the parent cubic L1(2) lattice, detected after adding 0.2 at. % Hf, are with modulations to the lattice constant (a) with a ratio (c/a), 2.04 and 0.87, respectively. Ab initio calculations of electronic and structural properties and hyperfine parameters at the Ta-181 ion probe of the gamma-Ni3Al-0.2 at. % Hf alloy were performed using the full potential augmented plane wave plus local-orbital (APW+lo) method as implemented in the WIEN2k code. The accuracy of the calculations and comparison with the experimental results enabled us to identify the observed hyperfine interactions and to infer the EFG sign that cannot be measured in conventional TDPAC measurements. (C) 2013 AIP Publishing LLC.
T2  - Journal of Applied Physics
T1  - Hf dopants in gamma -Ni3Al alloy
VL  - 114
IS  - 6
DO  - 10.1063/1.4818317
ER  - 
@article{
author = "Ivanovski, Valentin N. and Cekić, Božidar Đ. and Umićević, Ana and Belošević-Čavor, Jelena and Schumacher, G. and Koteski, Vasil J. and Barudžija, Tanja",
year = "2013",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/5625",
abstract = "The Time Differential Perturbed Angular (TDPAC) measurements of nuclear quadrupole interactions (NQIs) at Ta-181 ion probe in the polycrystalline intermetallic alloy gamma-Ni3Al doped with 0.2 at. % Hf were performed in the temperature range 78-1230K, in order to determine the lattice location of Hf atoms in the ordered gamma-Ni3Al structure. The two NQIs obtained are discussed within the present L1(2) cubic structure and a tetragonal distortion of L1(2) to another two DO22 and L6(0) type structures. The first low frequency NQI at the site of the Ta-181 ion-probe after substitution of aluminum for hafnium in DO22 at ambient temperature, is v(Q1)(300 K) = 39(1) MHz with eta(1) = 0. The corresponding high frequency value on the second crystallographic site in L6(0), is v(Q2)(300 K) = 204(14) MHz with eta(2) = 0.47(11). These two NQIs have different temperature behavior. The presence of both DO22 and L6(0) tetragonal distortions of the parent cubic L1(2) lattice, detected after adding 0.2 at. % Hf, are with modulations to the lattice constant (a) with a ratio (c/a), 2.04 and 0.87, respectively. Ab initio calculations of electronic and structural properties and hyperfine parameters at the Ta-181 ion probe of the gamma-Ni3Al-0.2 at. % Hf alloy were performed using the full potential augmented plane wave plus local-orbital (APW+lo) method as implemented in the WIEN2k code. The accuracy of the calculations and comparison with the experimental results enabled us to identify the observed hyperfine interactions and to infer the EFG sign that cannot be measured in conventional TDPAC measurements. (C) 2013 AIP Publishing LLC.",
journal = "Journal of Applied Physics",
title = "Hf dopants in gamma -Ni3Al alloy",
volume = "114",
number = "6",
doi = "10.1063/1.4818317"
}
Ivanovski, V. N., Cekić, B. Đ., Umićević, A., Belošević-Čavor, J., Schumacher, G., Koteski, V. J.,& Barudžija, T. (2013). Hf dopants in gamma -Ni3Al alloy.
Journal of Applied Physics, 114(6).
https://doi.org/10.1063/1.4818317
Ivanovski VN, Cekić BĐ, Umićević A, Belošević-Čavor J, Schumacher G, Koteski VJ, Barudžija T. Hf dopants in gamma -Ni3Al alloy. Journal of Applied Physics. 2013;114(6)
Ivanovski Valentin N., Cekić Božidar Đ., Umićević Ana, Belošević-Čavor Jelena, Schumacher G., Koteski Vasil J., Barudžija Tanja, "Hf dopants in gamma -Ni3Al alloy" Journal of Applied Physics, 114, no. 6 (2013),
https://doi.org/10.1063/1.4818317 .
3
3
3