Radojkovic, A.

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  • Radojkovic, A. (3)
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Author's Bibliography

Structural and electrical properties of BaCe(0.9)Ee(0.1)O(2.95) electrolyte for IT-SOFCs

Radojkovic, A.; Savić, S. M.; Jović, Nataša G.; Ćirković, Jovana; Despotovic, Z.; Ribic, A.; Brankovic, Z.; Branković, Goran O.

(2015)

TY  - JOUR
AU  - Radojkovic, A.
AU  - Savić, S. M.
AU  - Jović, Nataša G.
AU  - Ćirković, Jovana
AU  - Despotovic, Z.
AU  - Ribic, A.
AU  - Brankovic, Z.
AU  - Branković, Goran O.
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/472
AB  - BaCe(0.9)Ee(0.1)O(2.95) (BCE) nanopowder was synthesized by citric-nitric autocombustion method. Rietveld refinement analysis showed that unit cell volume was slightly larger compared with the most known BaCe0.9Y0.1O2.95, which might contribute to higher proton mobility. Sinterability of BaCeO3 is also enhanced by doping with Eu, since dense single-phased BCE electrolyte microstructure comprising of 1-2mm grains was obtained after sintering at 1450 degrees C for 5 h. The electrochemical impedance spectroscopy (EIS) analysis revealed separate bulk and grain boundary contributions to the total electrolyte conductivity below 200 degrees C. The grain boundary conductivity was one to two orders of magnitude lower than the bulk conductivity, indicating blocking effect of the grain boundaries to the mobility of charge carriers. This effect diminished completely above 500 degrees C and only total conductivities were determined between 500 and 700 degrees C. Conductivity of BCE in a wet hydrogen atmosphere at 600 degrees C reached 1.2 x 10(-2) S/cm, which can be considered as one of the highest conductivities among BaCeO3 based proton conductors. (C) 2015 Elsevier Ltd. All rights reserved.
T2  - Electrochimica Acta
T1  - Structural and electrical properties of BaCe(0.9)Ee(0.1)O(2.95) electrolyte for IT-SOFCs
VL  - 161
SP  - 153
EP  - 158
DO  - 10.1016/j.electacta.2015.02.075
ER  - 
@article{
author = "Radojkovic, A. and Savić, S. M. and Jović, Nataša G. and Ćirković, Jovana and Despotovic, Z. and Ribic, A. and Brankovic, Z. and Branković, Goran O.",
year = "2015",
abstract = "BaCe(0.9)Ee(0.1)O(2.95) (BCE) nanopowder was synthesized by citric-nitric autocombustion method. Rietveld refinement analysis showed that unit cell volume was slightly larger compared with the most known BaCe0.9Y0.1O2.95, which might contribute to higher proton mobility. Sinterability of BaCeO3 is also enhanced by doping with Eu, since dense single-phased BCE electrolyte microstructure comprising of 1-2mm grains was obtained after sintering at 1450 degrees C for 5 h. The electrochemical impedance spectroscopy (EIS) analysis revealed separate bulk and grain boundary contributions to the total electrolyte conductivity below 200 degrees C. The grain boundary conductivity was one to two orders of magnitude lower than the bulk conductivity, indicating blocking effect of the grain boundaries to the mobility of charge carriers. This effect diminished completely above 500 degrees C and only total conductivities were determined between 500 and 700 degrees C. Conductivity of BCE in a wet hydrogen atmosphere at 600 degrees C reached 1.2 x 10(-2) S/cm, which can be considered as one of the highest conductivities among BaCeO3 based proton conductors. (C) 2015 Elsevier Ltd. All rights reserved.",
journal = "Electrochimica Acta",
title = "Structural and electrical properties of BaCe(0.9)Ee(0.1)O(2.95) electrolyte for IT-SOFCs",
volume = "161",
pages = "153-158",
doi = "10.1016/j.electacta.2015.02.075"
}
Radojkovic, A., Savić, S. M., Jović, N. G., Ćirković, J., Despotovic, Z., Ribic, A., Brankovic, Z.,& Branković, G. O.. (2015). Structural and electrical properties of BaCe(0.9)Ee(0.1)O(2.95) electrolyte for IT-SOFCs. in Electrochimica Acta, 161, 153-158.
https://doi.org/10.1016/j.electacta.2015.02.075
Radojkovic A, Savić SM, Jović NG, Ćirković J, Despotovic Z, Ribic A, Brankovic Z, Branković GO. Structural and electrical properties of BaCe(0.9)Ee(0.1)O(2.95) electrolyte for IT-SOFCs. in Electrochimica Acta. 2015;161:153-158.
doi:10.1016/j.electacta.2015.02.075 .
Radojkovic, A., Savić, S. M., Jović, Nataša G., Ćirković, Jovana, Despotovic, Z., Ribic, A., Brankovic, Z., Branković, Goran O., "Structural and electrical properties of BaCe(0.9)Ee(0.1)O(2.95) electrolyte for IT-SOFCs" in Electrochimica Acta, 161 (2015):153-158,
https://doi.org/10.1016/j.electacta.2015.02.075 . .
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Sintering and electrical properties of Ce1-xBixO2-delta solid solution

Prekajski, Marija D.; Stojmenović, Marija; Radojkovic, A.; Branković, Goran O.; Oraon, H.; Subasri, R.; Matović, Branko

(2014)

TY  - JOUR
AU  - Prekajski, Marija D.
AU  - Stojmenović, Marija
AU  - Radojkovic, A.
AU  - Branković, Goran O.
AU  - Oraon, H.
AU  - Subasri, R.
AU  - Matović, Branko
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/187
AB  - Solid solution Ce1-xBixO2-delta nanopowders with the composition of x = 0.1-0.5 were synthesized by using Self Propagating Room Temperature procedure (SPRT). The results obtained by XRPD show that synthesized samples were single-phase solid solution at room temperature. Powders were densified by using Conventional (CS) and Microwave (MS) Sintering techniques at different temperatures, in an air atmosphere for 1 h. Scanning electron microscopy (SEM) and complex impedance method measurements were carried out on sintered samples. Maximum achieved density was for sample with Ce0.80Bi0.20O2-delta composition for both applied sintering techniques. The highest conductivity was obtained for the ceramic composition Ce0.80Bi0.20O2-delta sintered by microwave technique at 700 degrees C. (C) 2014 Elsevier B.V. All rights reserved.
T2  - Journal of Alloys and Compounds
T1  - Sintering and electrical properties of Ce1-xBixO2-delta solid solution
VL  - 617
SP  - 563
EP  - 568
DO  - 10.1016/j.jallcom.2014.08.090
ER  - 
@article{
author = "Prekajski, Marija D. and Stojmenović, Marija and Radojkovic, A. and Branković, Goran O. and Oraon, H. and Subasri, R. and Matović, Branko",
year = "2014",
abstract = "Solid solution Ce1-xBixO2-delta nanopowders with the composition of x = 0.1-0.5 were synthesized by using Self Propagating Room Temperature procedure (SPRT). The results obtained by XRPD show that synthesized samples were single-phase solid solution at room temperature. Powders were densified by using Conventional (CS) and Microwave (MS) Sintering techniques at different temperatures, in an air atmosphere for 1 h. Scanning electron microscopy (SEM) and complex impedance method measurements were carried out on sintered samples. Maximum achieved density was for sample with Ce0.80Bi0.20O2-delta composition for both applied sintering techniques. The highest conductivity was obtained for the ceramic composition Ce0.80Bi0.20O2-delta sintered by microwave technique at 700 degrees C. (C) 2014 Elsevier B.V. All rights reserved.",
journal = "Journal of Alloys and Compounds",
title = "Sintering and electrical properties of Ce1-xBixO2-delta solid solution",
volume = "617",
pages = "563-568",
doi = "10.1016/j.jallcom.2014.08.090"
}
Prekajski, M. D., Stojmenović, M., Radojkovic, A., Branković, G. O., Oraon, H., Subasri, R.,& Matović, B.. (2014). Sintering and electrical properties of Ce1-xBixO2-delta solid solution. in Journal of Alloys and Compounds, 617, 563-568.
https://doi.org/10.1016/j.jallcom.2014.08.090
Prekajski MD, Stojmenović M, Radojkovic A, Branković GO, Oraon H, Subasri R, Matović B. Sintering and electrical properties of Ce1-xBixO2-delta solid solution. in Journal of Alloys and Compounds. 2014;617:563-568.
doi:10.1016/j.jallcom.2014.08.090 .
Prekajski, Marija D., Stojmenović, Marija, Radojkovic, A., Branković, Goran O., Oraon, H., Subasri, R., Matović, Branko, "Sintering and electrical properties of Ce1-xBixO2-delta solid solution" in Journal of Alloys and Compounds, 617 (2014):563-568,
https://doi.org/10.1016/j.jallcom.2014.08.090 . .
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Magnetic properties of NiMn2O4-delta (nickel manganite): Multiple magnetic phase transitions and exchange bias effect

Tadić, Marin; Savić, S. M.; Jagličić, Zvonko; Vojisavljevic, K.; Radojkovic, A.; Prsic, S.; Nikolic, Dobrica

(2014)

TY  - JOUR
AU  - Tadić, Marin
AU  - Savić, S. M.
AU  - Jagličić, Zvonko
AU  - Vojisavljevic, K.
AU  - Radojkovic, A.
AU  - Prsic, S.
AU  - Nikolic, Dobrica
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/5850
AB  - We present magnetic properties of NiMn2O4-delta (nickel manganite) which was synthesized by complex polymerization synthesis method followed by successive heat treatment and final calcinations in air at 1200 degrees C. The sample was characterized by using X-ray powder diffractometer (XRPD), scanning electron microscopy (SEM), field-emission scanning electron microscopy (FE-SEM) and superconducting quantum interference device (SQUID) magnetometer. The XRPD and FE-SEM studies revealed NiMn2O4-delta phase and good crystallinity of particles. No other impurities have been observed by XRPD. The magnetic properties of the sample have been studied by measuring the temperature and field dependence of magnetization. Magnetic measurements of M(T) reveal rather complex magnetic properties and multiple magnetic phase transitions. We show three magnetic phase transitions with transition temperatures at T-M1 = 35 K (long-range antiferromagnetic transition), T-M2 = 101 K (antiferromagnetic-type transition) and T-M3 = 120 K (ferromagnetic-like transition). We found that the T-M1 transition is strongly dependent on the strength of the applied magnetic field (T-M1 decreases with increasing applied field) whereas the T-M3 is field independent. Otherwise, the T-M2 maximum almost disappears in higher applied magnetic fields (H = 1 kOe and 10 kOe). Magnetic measurements of M(H) show hysteretic behavior below T-M3. Moreover, hysteresis properties measured after cooling of the sample in magnetic field of 10 kOe show exchange bias effect with an exchange bias field vertical bar H-EB vertical bar= 196 Oe. In summary, the properties that distinguish the investigated NiMn2O4-delta sample from other bulk, thin film, ceramic and nanoparticle NiMn2O4-delta systems are the triple magnetic transitions with sharp increase of the ZFC and FC magnetizations at 120 K and the exchange bias effect. The analysis of the results and comparison with literature data allowed us to conjecture that the mixed oxidation states of Mn ions, ferromagnetic and antiferromagnetic sublattice orders and surface effects in the sample tailor these interesting magnetic properties. (C) 2013 Elsevier B. V. All rights reserved.
T2  - Journal of Alloys and Compounds
T1  - Magnetic properties of NiMn2O4-delta (nickel manganite): Multiple magnetic phase transitions and exchange bias effect
VL  - 588
SP  - 465
EP  - 469
DO  - 10.1016/j.jallcom.2013.11.025
ER  - 
@article{
author = "Tadić, Marin and Savić, S. M. and Jagličić, Zvonko and Vojisavljevic, K. and Radojkovic, A. and Prsic, S. and Nikolic, Dobrica",
year = "2014",
abstract = "We present magnetic properties of NiMn2O4-delta (nickel manganite) which was synthesized by complex polymerization synthesis method followed by successive heat treatment and final calcinations in air at 1200 degrees C. The sample was characterized by using X-ray powder diffractometer (XRPD), scanning electron microscopy (SEM), field-emission scanning electron microscopy (FE-SEM) and superconducting quantum interference device (SQUID) magnetometer. The XRPD and FE-SEM studies revealed NiMn2O4-delta phase and good crystallinity of particles. No other impurities have been observed by XRPD. The magnetic properties of the sample have been studied by measuring the temperature and field dependence of magnetization. Magnetic measurements of M(T) reveal rather complex magnetic properties and multiple magnetic phase transitions. We show three magnetic phase transitions with transition temperatures at T-M1 = 35 K (long-range antiferromagnetic transition), T-M2 = 101 K (antiferromagnetic-type transition) and T-M3 = 120 K (ferromagnetic-like transition). We found that the T-M1 transition is strongly dependent on the strength of the applied magnetic field (T-M1 decreases with increasing applied field) whereas the T-M3 is field independent. Otherwise, the T-M2 maximum almost disappears in higher applied magnetic fields (H = 1 kOe and 10 kOe). Magnetic measurements of M(H) show hysteretic behavior below T-M3. Moreover, hysteresis properties measured after cooling of the sample in magnetic field of 10 kOe show exchange bias effect with an exchange bias field vertical bar H-EB vertical bar= 196 Oe. In summary, the properties that distinguish the investigated NiMn2O4-delta sample from other bulk, thin film, ceramic and nanoparticle NiMn2O4-delta systems are the triple magnetic transitions with sharp increase of the ZFC and FC magnetizations at 120 K and the exchange bias effect. The analysis of the results and comparison with literature data allowed us to conjecture that the mixed oxidation states of Mn ions, ferromagnetic and antiferromagnetic sublattice orders and surface effects in the sample tailor these interesting magnetic properties. (C) 2013 Elsevier B. V. All rights reserved.",
journal = "Journal of Alloys and Compounds",
title = "Magnetic properties of NiMn2O4-delta (nickel manganite): Multiple magnetic phase transitions and exchange bias effect",
volume = "588",
pages = "465-469",
doi = "10.1016/j.jallcom.2013.11.025"
}
Tadić, M., Savić, S. M., Jagličić, Z., Vojisavljevic, K., Radojkovic, A., Prsic, S.,& Nikolic, D.. (2014). Magnetic properties of NiMn2O4-delta (nickel manganite): Multiple magnetic phase transitions and exchange bias effect. in Journal of Alloys and Compounds, 588, 465-469.
https://doi.org/10.1016/j.jallcom.2013.11.025
Tadić M, Savić SM, Jagličić Z, Vojisavljevic K, Radojkovic A, Prsic S, Nikolic D. Magnetic properties of NiMn2O4-delta (nickel manganite): Multiple magnetic phase transitions and exchange bias effect. in Journal of Alloys and Compounds. 2014;588:465-469.
doi:10.1016/j.jallcom.2013.11.025 .
Tadić, Marin, Savić, S. M., Jagličić, Zvonko, Vojisavljevic, K., Radojkovic, A., Prsic, S., Nikolic, Dobrica, "Magnetic properties of NiMn2O4-delta (nickel manganite): Multiple magnetic phase transitions and exchange bias effect" in Journal of Alloys and Compounds, 588 (2014):465-469,
https://doi.org/10.1016/j.jallcom.2013.11.025 . .
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