TY  - JOUR
AU  - Martin, Catalin
AU  - Martinez, V. A.
AU  - Opačić, Marko R.
AU  - Đurđić-Mijin, Sanja
AU  - Mitrić, Petar
AU  - Umićević, Ana
AU  - Poudel, A.
AU  - Sydoryk, Ihor
AU  - Ren, Weijun
AU  - Martin, Ruaridh M.
AU  - Tanner, David B.
AU  - Lazarević, Nenad
AU  - Petrović, Čedomir
AU  - Tanasković, Darko
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10987
AB  - Intermetallic narrow-gap semiconductors have been intensively explored due to their large thermoelectric power at low temperatures and a possible role of strong electronic correlations in their unusual thermodynamic and transport properties. Here we study the optical spectra and vibrational properties of FeGa3 single crystal. The optical conductivity indicates that FeGa3 has a direct band gap of ≈0.7 eV, consistent with density functional theory (DFT) calculations. Most importantly, we find a substantial spectral weight also below 0.4 eV, which is the energy of the indirect (charge) gap found in resistivity measurements and ab initio calculations. We find that the spectral weight below the gap decreases with increasing temperature, which indicates that it originates from the impurity states and not from the electronic correlations. Interestingly, we did not find any signatures of the impurity states in vibrational spectra. The infrared and Raman vibrational lines are narrow and weakly temperature dependent. The vibrational frequencies are in excellent agreement with our DFT calculations, implying a modest role of electronic correlations. Narrow Mössbauer spectral lines also indicate high crystallinity of the sample. © 2023 American Physical Society.
T2  - Physical Review B
T1  - Optical conductivity and vibrational spectra of the narrow-gap semiconductor FeGa3
VL  - 107
IS  - 16
DO  - 10.1103/PhysRevB.107.165151
ER  - 

@article{
author = "Martin, Catalin and Martinez, V. A. and Opačić, Marko R. and Đurđić-Mijin, Sanja and Mitrić, Petar and Umićević, Ana and Poudel, A. and Sydoryk, Ihor and Ren, Weijun and Martin, Ruaridh M. and Tanner, David B. and Lazarević, Nenad and Petrović, Čedomir and Tanasković, Darko",
year = "2023",
abstract = "Intermetallic narrow-gap semiconductors have been intensively explored due to their large thermoelectric power at low temperatures and a possible role of strong electronic correlations in their unusual thermodynamic and transport properties. Here we study the optical spectra and vibrational properties of FeGa3 single crystal. The optical conductivity indicates that FeGa3 has a direct band gap of ≈0.7 eV, consistent with density functional theory (DFT) calculations. Most importantly, we find a substantial spectral weight also below 0.4 eV, which is the energy of the indirect (charge) gap found in resistivity measurements and ab initio calculations. We find that the spectral weight below the gap decreases with increasing temperature, which indicates that it originates from the impurity states and not from the electronic correlations. Interestingly, we did not find any signatures of the impurity states in vibrational spectra. The infrared and Raman vibrational lines are narrow and weakly temperature dependent. The vibrational frequencies are in excellent agreement with our DFT calculations, implying a modest role of electronic correlations. Narrow Mössbauer spectral lines also indicate high crystallinity of the sample. © 2023 American Physical Society.",
journal = "Physical Review B",
title = "Optical conductivity and vibrational spectra of the narrow-gap semiconductor FeGa3",
volume = "107",
number = "16",
doi = "10.1103/PhysRevB.107.165151"
}

Martin, C., Martinez, V. A., Opačić, M. R., Đurđić-Mijin, S., Mitrić, P., Umićević, A., Poudel, A., Sydoryk, I., Ren, W., Martin, R. M., Tanner, D. B., Lazarević, N., Petrović, Č.,& Tanasković, D.. (2023). Optical conductivity and vibrational spectra of the narrow-gap semiconductor FeGa3. in Physical Review B, 107(16).
https://doi.org/10.1103/PhysRevB.107.165151

Martin C, Martinez VA, Opačić MR, Đurđić-Mijin S, Mitrić P, Umićević A, Poudel A, Sydoryk I, Ren W, Martin RM, Tanner DB, Lazarević N, Petrović Č, Tanasković D. Optical conductivity and vibrational spectra of the narrow-gap semiconductor FeGa3. in Physical Review B. 2023;107(16).
doi:10.1103/PhysRevB.107.165151 .

Martin, Catalin, Martinez, V. A., Opačić, Marko R., Đurđić-Mijin, Sanja, Mitrić, Petar, Umićević, Ana, Poudel, A., Sydoryk, Ihor, Ren, Weijun, Martin, Ruaridh M., Tanner, David B., Lazarević, Nenad, Petrović, Čedomir, Tanasković, Darko, "Optical conductivity and vibrational spectra of the narrow-gap semiconductor FeGa3" in Physical Review B, 107, no. 16 (2023),
https://doi.org/10.1103/PhysRevB.107.165151 . .

TY  - JOUR
AU  - Wu, Xueliang
AU  - Hu, Zhixiang
AU  - Graf, David
AU  - Liu, Yu
AU  - Deng, Chaoyue
AU  - Fu, Huixia
AU  - Kundu, Asish K.
AU  - Valla, Tonica
AU  - Petrović, Čedomir
AU  - Wang, Aifeng
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12448
AB  - We report a comprehensive study of magnetotransport properties, angle-resolved photoemission spectroscopy (ARPES), and density functional theory (DFT) calculations on self-flux grown LaAuSb2 single crystals. Resistivity and Hall measurements reveal a charge density wave (CDW) transition at 77 K. MR and de Haas-van Alphen measurements indicate that the transport properties of LaAuSb2 are dominated by Dirac fermions that arise from Sb square nets. ARPES measurements and DFT calculations reveal an electronic structure with a common feature of the square-net-based topological semimetals, which is in good agreement with the magnetotransport properties. Our results indicate the coexistence of CDW and Dirac fermion in LaAuSb2, both of which are linked to the bands arising from the Sb square net, suggesting that the square net could serve as a structural motif to explore various electronic orders.
T2  - Physical Review B
T1  - Coexistence of Dirac fermion and charge density wave in the square-net-based semimetal LaAuSb2
VL  - 108
IS  - 24
DO  - 10.1103/PhysRevB.108.245156
ER  - 

@article{
author = "Wu, Xueliang and Hu, Zhixiang and Graf, David and Liu, Yu and Deng, Chaoyue and Fu, Huixia and Kundu, Asish K. and Valla, Tonica and Petrović, Čedomir and Wang, Aifeng",
year = "2023",
abstract = "We report a comprehensive study of magnetotransport properties, angle-resolved photoemission spectroscopy (ARPES), and density functional theory (DFT) calculations on self-flux grown LaAuSb2 single crystals. Resistivity and Hall measurements reveal a charge density wave (CDW) transition at 77 K. MR and de Haas-van Alphen measurements indicate that the transport properties of LaAuSb2 are dominated by Dirac fermions that arise from Sb square nets. ARPES measurements and DFT calculations reveal an electronic structure with a common feature of the square-net-based topological semimetals, which is in good agreement with the magnetotransport properties. Our results indicate the coexistence of CDW and Dirac fermion in LaAuSb2, both of which are linked to the bands arising from the Sb square net, suggesting that the square net could serve as a structural motif to explore various electronic orders.",
journal = "Physical Review B",
title = "Coexistence of Dirac fermion and charge density wave in the square-net-based semimetal LaAuSb2",
volume = "108",
number = "24",
doi = "10.1103/PhysRevB.108.245156"
}

Wu, X., Hu, Z., Graf, D., Liu, Y., Deng, C., Fu, H., Kundu, A. K., Valla, T., Petrović, Č.,& Wang, A.. (2023). Coexistence of Dirac fermion and charge density wave in the square-net-based semimetal LaAuSb2. in Physical Review B, 108(24).
https://doi.org/10.1103/PhysRevB.108.245156

Wu X, Hu Z, Graf D, Liu Y, Deng C, Fu H, Kundu AK, Valla T, Petrović Č, Wang A. Coexistence of Dirac fermion and charge density wave in the square-net-based semimetal LaAuSb2. in Physical Review B. 2023;108(24).
doi:10.1103/PhysRevB.108.245156 .

Wu, Xueliang, Hu, Zhixiang, Graf, David, Liu, Yu, Deng, Chaoyue, Fu, Huixia, Kundu, Asish K., Valla, Tonica, Petrović, Čedomir, Wang, Aifeng, "Coexistence of Dirac fermion and charge density wave in the square-net-based semimetal LaAuSb2" in Physical Review B, 108, no. 24 (2023),
https://doi.org/10.1103/PhysRevB.108.245156 . .

TY  - JOUR
AU  - Liu, Yu
AU  - Wang, Aifeng
AU  - Ivanovski, Valentin N.
AU  - Du, Qianheng
AU  - Koteski, Vasil J.
AU  - Petrović, Čedomir
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10174
AB  - We report thermoelectric studies of FeS1-xSex (x=0,0.06) superconducting single crystals that feature high irreversibility fields and critical current density Jc comparable to materials with much higher superconducting critical temperatures (Tc's). The ratio of Tc to the Fermi temperature TF is very small, indicating weak electronic correlations. With a slight selenium substitution on sulfur site in FeS both Tc/TF and the effective mass m∗ rise considerably, implying increase in electronic correlation of the bulk conducting states. The first-principle calculations show rise of the density of states at the Fermi level in FeS0.94Se0.06 when compared to FeS, which is related not only to Fe but also to chalcogen-derived electronic states.
T2  - Physical Review B
T1  - Thermoelectricity and electronic correlation enhancement in FeS by light Se doping
VL  - 105
IS  - 4
SP  - 045133
DO  - 10.1103/PhysRevB.105.045133
ER  - 

@article{
author = "Liu, Yu and Wang, Aifeng and Ivanovski, Valentin N. and Du, Qianheng and Koteski, Vasil J. and Petrović, Čedomir",
year = "2022",
abstract = "We report thermoelectric studies of FeS1-xSex (x=0,0.06) superconducting single crystals that feature high irreversibility fields and critical current density Jc comparable to materials with much higher superconducting critical temperatures (Tc's). The ratio of Tc to the Fermi temperature TF is very small, indicating weak electronic correlations. With a slight selenium substitution on sulfur site in FeS both Tc/TF and the effective mass m∗ rise considerably, implying increase in electronic correlation of the bulk conducting states. The first-principle calculations show rise of the density of states at the Fermi level in FeS0.94Se0.06 when compared to FeS, which is related not only to Fe but also to chalcogen-derived electronic states.",
journal = "Physical Review B",
title = "Thermoelectricity and electronic correlation enhancement in FeS by light Se doping",
volume = "105",
number = "4",
pages = "045133",
doi = "10.1103/PhysRevB.105.045133"
}

Liu, Y., Wang, A., Ivanovski, V. N., Du, Q., Koteski, V. J.,& Petrović, Č.. (2022). Thermoelectricity and electronic correlation enhancement in FeS by light Se doping. in Physical Review B, 105(4), 045133.
https://doi.org/10.1103/PhysRevB.105.045133

Liu Y, Wang A, Ivanovski VN, Du Q, Koteski VJ, Petrović Č. Thermoelectricity and electronic correlation enhancement in FeS by light Se doping. in Physical Review B. 2022;105(4):045133.
doi:10.1103/PhysRevB.105.045133 .

Liu, Yu, Wang, Aifeng, Ivanovski, Valentin N., Du, Qianheng, Koteski, Vasil J., Petrović, Čedomir, "Thermoelectricity and electronic correlation enhancement in FeS by light Se doping" in Physical Review B, 105, no. 4 (2022):045133,
https://doi.org/10.1103/PhysRevB.105.045133 . .

TY  - JOUR
AU  - Liu, Yu
AU  - Tong, Xiao
AU  - Ivanovski, Valentin N.
AU  - Hu, Zhixiang
AU  - Leshchev, Denis
AU  - Zhu, Xiangde
AU  - Lei, Hechang
AU  - Stavitski, Eli
AU  - Attenkofer, Klaus
AU  - Koteski, Vasil J.
AU  - Petrović, Čedomir
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10479
AB  - Charge density waves (CDWs) with superconductivity, competing Fermi surface instabilities, and collective orders have captured much interest in two-dimensional van der Waals (vdW) materials. Understanding the CDW suppression mechanism, its connection to the emerging superconducting state, and electronic correlations provides opportunities for engineering the electronic properties of vdW heterostructures and thin-film devices. Using a combination of the thermal transport, x-ray photoemission spectroscopy, Raman measurements, and first-principles calculations, we observe an increase in electronic correlations of the conducting states as the CDW is suppressed in ZrTe3 with 5% Cu and Ni intercalation in the vdW gap. As superconductivity emerges, intercalation brings not only decoupling of quasi-one-dimensional conduction electrons with phonons as a consequence of intercalation-induced lattice expansion but also a drastic increase in Zr2+ at the expense of Zr4+ metal atoms. These observations not only demonstrate the potential of atomic intercalates in the vdW gap for ground-state tuning but also illustrate the crucial role of the Zr metal valence in the formation of collective electronic orders.
T2  - Physical Review B
T1  - Enhanced superconductivity and electron correlations in intercalated ZrTe3
VL  - 106
IS  - 16
SP  - 165113
DO  - 10.1103/PhysRevB.106.165113
ER  - 

@article{
author = "Liu, Yu and Tong, Xiao and Ivanovski, Valentin N. and Hu, Zhixiang and Leshchev, Denis and Zhu, Xiangde and Lei, Hechang and Stavitski, Eli and Attenkofer, Klaus and Koteski, Vasil J. and Petrović, Čedomir",
year = "2022",
abstract = "Charge density waves (CDWs) with superconductivity, competing Fermi surface instabilities, and collective orders have captured much interest in two-dimensional van der Waals (vdW) materials. Understanding the CDW suppression mechanism, its connection to the emerging superconducting state, and electronic correlations provides opportunities for engineering the electronic properties of vdW heterostructures and thin-film devices. Using a combination of the thermal transport, x-ray photoemission spectroscopy, Raman measurements, and first-principles calculations, we observe an increase in electronic correlations of the conducting states as the CDW is suppressed in ZrTe3 with 5% Cu and Ni intercalation in the vdW gap. As superconductivity emerges, intercalation brings not only decoupling of quasi-one-dimensional conduction electrons with phonons as a consequence of intercalation-induced lattice expansion but also a drastic increase in Zr2+ at the expense of Zr4+ metal atoms. These observations not only demonstrate the potential of atomic intercalates in the vdW gap for ground-state tuning but also illustrate the crucial role of the Zr metal valence in the formation of collective electronic orders.",
journal = "Physical Review B",
title = "Enhanced superconductivity and electron correlations in intercalated ZrTe3",
volume = "106",
number = "16",
pages = "165113",
doi = "10.1103/PhysRevB.106.165113"
}

Liu, Y., Tong, X., Ivanovski, V. N., Hu, Z., Leshchev, D., Zhu, X., Lei, H., Stavitski, E., Attenkofer, K., Koteski, V. J.,& Petrović, Č.. (2022). Enhanced superconductivity and electron correlations in intercalated ZrTe3. in Physical Review B, 106(16), 165113.
https://doi.org/10.1103/PhysRevB.106.165113

Liu Y, Tong X, Ivanovski VN, Hu Z, Leshchev D, Zhu X, Lei H, Stavitski E, Attenkofer K, Koteski VJ, Petrović Č. Enhanced superconductivity and electron correlations in intercalated ZrTe3. in Physical Review B. 2022;106(16):165113.
doi:10.1103/PhysRevB.106.165113 .

Liu, Yu, Tong, Xiao, Ivanovski, Valentin N., Hu, Zhixiang, Leshchev, Denis, Zhu, Xiangde, Lei, Hechang, Stavitski, Eli, Attenkofer, Klaus, Koteski, Vasil J., Petrović, Čedomir, "Enhanced superconductivity and electron correlations in intercalated ZrTe3" in Physical Review B, 106, no. 16 (2022):165113,
https://doi.org/10.1103/PhysRevB.106.165113 . .

TY  - JOUR
AU  - Wang, Aifeng
AU  - Milosavljević, Ana
AU  - Abeykoon, A. M. Milinda
AU  - Ivanovski, Valentin N.
AU  - Du, Qianheng
AU  - Baum, Andreas
AU  - Stavitski, Eli
AU  - Liu, Yu
AU  - Lazarević, Nenad
AU  - Attenkofer, Klaus
AU  - Hackl, Rudi
AU  - Popović, Zoran
AU  - Petrović, Čedomir
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10380
AB  - Connections between crystal chemistry and critical temperature Tc have been in the focus of superconductivity, one of the most widely studied phenomena in physics, chemistry, and materials science alike. In most Fe-based superconductors, materials chemistry and physics conspire so that Tc correlates with the average anion height above the Fe plane, i.e., with the geometry of the FeAs4 or FeCh4 (Ch = Te, Se, or S) tetrahedron. By synthesizing Fe1–ySe1–xSx (0 ≤ x ≤ 1; y ≤ 0.1), we find that in alloyed crystals Tc is not correlated with the anion height like it is for most other Fe superconductors. Instead, changes in Tc(x) and tetragonal-to-orthorhombic (nematic) transition Ts(x) upon cooling are correlated with disorder in Fe vibrations in the direction orthogonal to Fe planes, along the crystallographic c-axis. The disorder stems from the random nature of S substitution, causing deformed Fe(Se,S)4 tetrahedra with different Fe–Se and Fe–S bond distances. Our results provide evidence of Tc and Ts suppression by disorder in anion height. The connection to local crystal chemistry may be exploited in computational prediction of new superconducting materials with FeSe/S building blocks.
T2  - Inorganic Chemistry
T1  - Suppression of Superconductivity and Nematic Order in Fe1–ySe1–xSx (0 ≤ x ≤ 1; y ≤ 0.1) Crystals by Anion Height Disorder
VL  - 61
IS  - 29
SP  - 11036
EP  - 11045
DO  - 10.1021/acs.inorgchem.2c00568
ER  - 

@article{
author = "Wang, Aifeng and Milosavljević, Ana and Abeykoon, A. M. Milinda and Ivanovski, Valentin N. and Du, Qianheng and Baum, Andreas and Stavitski, Eli and Liu, Yu and Lazarević, Nenad and Attenkofer, Klaus and Hackl, Rudi and Popović, Zoran and Petrović, Čedomir",
year = "2022",
abstract = "Connections between crystal chemistry and critical temperature Tc have been in the focus of superconductivity, one of the most widely studied phenomena in physics, chemistry, and materials science alike. In most Fe-based superconductors, materials chemistry and physics conspire so that Tc correlates with the average anion height above the Fe plane, i.e., with the geometry of the FeAs4 or FeCh4 (Ch = Te, Se, or S) tetrahedron. By synthesizing Fe1–ySe1–xSx (0 ≤ x ≤ 1; y ≤ 0.1), we find that in alloyed crystals Tc is not correlated with the anion height like it is for most other Fe superconductors. Instead, changes in Tc(x) and tetragonal-to-orthorhombic (nematic) transition Ts(x) upon cooling are correlated with disorder in Fe vibrations in the direction orthogonal to Fe planes, along the crystallographic c-axis. The disorder stems from the random nature of S substitution, causing deformed Fe(Se,S)4 tetrahedra with different Fe–Se and Fe–S bond distances. Our results provide evidence of Tc and Ts suppression by disorder in anion height. The connection to local crystal chemistry may be exploited in computational prediction of new superconducting materials with FeSe/S building blocks.",
journal = "Inorganic Chemistry",
title = "Suppression of Superconductivity and Nematic Order in Fe1–ySe1–xSx (0 ≤ x ≤ 1; y ≤ 0.1) Crystals by Anion Height Disorder",
volume = "61",
number = "29",
pages = "11036-11045",
doi = "10.1021/acs.inorgchem.2c00568"
}

Wang, A., Milosavljević, A., Abeykoon, A. M. M., Ivanovski, V. N., Du, Q., Baum, A., Stavitski, E., Liu, Y., Lazarević, N., Attenkofer, K., Hackl, R., Popović, Z.,& Petrović, Č.. (2022). Suppression of Superconductivity and Nematic Order in Fe1–ySe1–xSx (0 ≤ x ≤ 1; y ≤ 0.1) Crystals by Anion Height Disorder. in Inorganic Chemistry, 61(29), 11036-11045.
https://doi.org/10.1021/acs.inorgchem.2c00568

Wang A, Milosavljević A, Abeykoon AMM, Ivanovski VN, Du Q, Baum A, Stavitski E, Liu Y, Lazarević N, Attenkofer K, Hackl R, Popović Z, Petrović Č. Suppression of Superconductivity and Nematic Order in Fe1–ySe1–xSx (0 ≤ x ≤ 1; y ≤ 0.1) Crystals by Anion Height Disorder. in Inorganic Chemistry. 2022;61(29):11036-11045.
doi:10.1021/acs.inorgchem.2c00568 .

Wang, Aifeng, Milosavljević, Ana, Abeykoon, A. M. Milinda, Ivanovski, Valentin N., Du, Qianheng, Baum, Andreas, Stavitski, Eli, Liu, Yu, Lazarević, Nenad, Attenkofer, Klaus, Hackl, Rudi, Popović, Zoran, Petrović, Čedomir, "Suppression of Superconductivity and Nematic Order in Fe1–ySe1–xSx (0 ≤ x ≤ 1; y ≤ 0.1) Crystals by Anion Height Disorder" in Inorganic Chemistry, 61, no. 29 (2022):11036-11045,
https://doi.org/10.1021/acs.inorgchem.2c00568 . .

TY  - JOUR
AU  - Tian, Jianjun
AU  - Ivanovski, Valentin N.
AU  - Abeykoon, Milinda
AU  - Martin, Rodica M.
AU  - Baranets, Sviatoslav
AU  - Martin, Catalin
AU  - Liu, Yu
AU  - Du, Qianheng
AU  - Wang, Aifeng
AU  - Chen, Shuzhang
AU  - Tong, Xiao
AU  - Zhang, Weifeng
AU  - Bobev, Svilen
AU  - Koteski, Vasil J.
AU  - Petrović, Čedomir
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10108
AB  - Transition metal dichalcogenides attract considerable attention due to a variety of interesting properties, including long-range magnetism in nanocrystals. Here we investigate the magnetic, thermal, and electrical properties of an FeTe2 single crystal with iron vacancy defects. Magnetic measurements show a paramagnetic state and the absence of magnetic order with low anisotropy in the magnetic susceptibility. Fe 3d orbitals are well hybridized, contributing to the bad metal electrical resistivity. Observed thermal conductivity values below room temperature are rather low and comparable to those of high-performance thermoelectric materials. Our results indicate that FeTe2 can form in a highly defective marcasite crystal structure which can be exploited in future materials design.
T2  - Physical Review B
T1  - Absence of long-range magnetic order in Fe1−δ Te2  (δ ≈ 0.1) crystals
VL  - 104
IS  - 22
SP  - 224109
DO  - 10.1103/PhysRevB.104.224109
ER  - 

@article{
author = "Tian, Jianjun and Ivanovski, Valentin N. and Abeykoon, Milinda and Martin, Rodica M. and Baranets, Sviatoslav and Martin, Catalin and Liu, Yu and Du, Qianheng and Wang, Aifeng and Chen, Shuzhang and Tong, Xiao and Zhang, Weifeng and Bobev, Svilen and Koteski, Vasil J. and Petrović, Čedomir",
year = "2021",
abstract = "Transition metal dichalcogenides attract considerable attention due to a variety of interesting properties, including long-range magnetism in nanocrystals. Here we investigate the magnetic, thermal, and electrical properties of an FeTe2 single crystal with iron vacancy defects. Magnetic measurements show a paramagnetic state and the absence of magnetic order with low anisotropy in the magnetic susceptibility. Fe 3d orbitals are well hybridized, contributing to the bad metal electrical resistivity. Observed thermal conductivity values below room temperature are rather low and comparable to those of high-performance thermoelectric materials. Our results indicate that FeTe2 can form in a highly defective marcasite crystal structure which can be exploited in future materials design.",
journal = "Physical Review B",
title = "Absence of long-range magnetic order in Fe1−δ Te2  (δ ≈ 0.1) crystals",
volume = "104",
number = "22",
pages = "224109",
doi = "10.1103/PhysRevB.104.224109"
}

Tian, J., Ivanovski, V. N., Abeykoon, M., Martin, R. M., Baranets, S., Martin, C., Liu, Y., Du, Q., Wang, A., Chen, S., Tong, X., Zhang, W., Bobev, S., Koteski, V. J.,& Petrović, Č.. (2021). Absence of long-range magnetic order in Fe1−δ Te2  (δ ≈ 0.1) crystals. in Physical Review B, 104(22), 224109.
https://doi.org/10.1103/PhysRevB.104.224109

Tian J, Ivanovski VN, Abeykoon M, Martin RM, Baranets S, Martin C, Liu Y, Du Q, Wang A, Chen S, Tong X, Zhang W, Bobev S, Koteski VJ, Petrović Č. Absence of long-range magnetic order in Fe1−δ Te2  (δ ≈ 0.1) crystals. in Physical Review B. 2021;104(22):224109.
doi:10.1103/PhysRevB.104.224109 .

Tian, Jianjun, Ivanovski, Valentin N., Abeykoon, Milinda, Martin, Rodica M., Baranets, Sviatoslav, Martin, Catalin, Liu, Yu, Du, Qianheng, Wang, Aifeng, Chen, Shuzhang, Tong, Xiao, Zhang, Weifeng, Bobev, Svilen, Koteski, Vasil J., Petrović, Čedomir, "Absence of long-range magnetic order in Fe1−δ Te2  (δ ≈ 0.1) crystals" in Physical Review B, 104, no. 22 (2021):224109,
https://doi.org/10.1103/PhysRevB.104.224109 . .

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  - https://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",
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. in 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. in Inorganic Chemistry. 2019;58(5):3107-3114.
doi:10.1021/acs.inorgchem.8b03089 .

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" in Inorganic Chemistry, 58, no. 5 (2019):3107-3114,
https://doi.org/10.1021/acs.inorgchem.8b03089 . .

TY  - JOUR
AU  - Liu, Yu
AU  - Ivanovski, Valentin N.
AU  - Petrović, Čedomir
PY  - 2017
UR  - https://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 Petrović, Čedomir",
year = "2017",
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.,& Petrović, Č.. (2017). Critical behavior of the van derWaals bonded ferromagnet Fe3-xGeTe2. in Physical Review B: Condensed Matter and Materials Physics, 96(14).
https://doi.org/10.1103/PhysRevB.96.144429

Liu Y, Ivanovski VN, Petrović Č. Critical behavior of the van derWaals bonded ferromagnet Fe3-xGeTe2. in Physical Review B: Condensed Matter and Materials Physics. 2017;96(14).
doi:10.1103/PhysRevB.96.144429 .

Liu, Yu, Ivanovski, Valentin N., Petrović, Čedomir, "Critical behavior of the van derWaals bonded ferromagnet Fe3-xGeTe2" in Physical Review B: Condensed Matter and Materials Physics, 96, no. 14 (2017),
https://doi.org/10.1103/PhysRevB.96.144429 . .

TY  - JOUR
AU  - Wang, Aifeng
AU  - Wu, Lijun
AU  - Ivanovski, Valentin N.
AU  - Warren, J. B.
AU  - Tian, Jianjun
AU  - Zhu, Yimei
AU  - Petrović, Čedomir
PY  - 2016
UR  - https://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 Petrović, Čedomir",
year = "2016",
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.,& Petrović, Č.. (2016). Critical current density and vortex pinning in tetragonal FeS1-xSex (x=0,0.06). in 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, Petrović Č. Critical current density and vortex pinning in tetragonal FeS1-xSex (x=0,0.06). in Physical Review B: Condensed Matter and Materials Physics. 2016;94(9).
doi:10.1103/PhysRevB.94.094506 .

Wang, Aifeng, Wu, Lijun, Ivanovski, Valentin N., Warren, J. B., Tian, Jianjun, Zhu, Yimei, Petrović, Čedomir, "Critical current density and vortex pinning in tetragonal FeS1-xSex (x=0,0.06)" in Physical Review B: Condensed Matter and Materials Physics, 94, no. 9 (2016),
https://doi.org/10.1103/PhysRevB.94.094506 . .

TY  - JOUR
AU  - Shi, Xun 

AU  - Richard, Pierre
AU  - Wang, Kefeng
AU  - 
Liu, Mian 
AU  - Matt, Christian Egon
AU  - Xu, N.
AU  - Dhaka, Rajendra S.
AU  - Ristić, Zoran
AU  - Qian, T.
AU  - Yang, Yi-feng
AU  - Petrović, Čedomir
AU  - Shi, M.
AU  - Ding, Hong
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/940
AB  - We present a combined angle-resolved photoemission spectroscopy (ARPES) and first-principles calculations study of the electronic structure of LaAgSb2 in the entire first Brillouin zone. We observe a Dirac-cone-like structure in the vicinity of the Fermi level formed by the crossing of two linear energy bands, as well as the nested segments of a Fermi surface pocket emerging from the cone. Our ARPES results show the close relationship of the Dirac cone to the charge-density-wave ordering, providing consistent explanations for exotic behaviors in this material.
T2  - Physical Review B: Condensed Matter and Materials Physics
T1  - Observation of Dirac-like band dispersion in LaAgSb2
VL  - 93
IS  - 8
DO  - 10.1103/PhysRevB.93.081105
ER  - 

@article{
author = "Shi, Xun 
 and Richard, Pierre and Wang, Kefeng and 
Liu, Mian  and Matt, Christian Egon and Xu, N. and Dhaka, Rajendra S. and Ristić, Zoran and Qian, T. and Yang, Yi-feng and Petrović, Čedomir and Shi, M. and Ding, Hong",
year = "2016",
abstract = "We present a combined angle-resolved photoemission spectroscopy (ARPES) and first-principles calculations study of the electronic structure of LaAgSb2 in the entire first Brillouin zone. We observe a Dirac-cone-like structure in the vicinity of the Fermi level formed by the crossing of two linear energy bands, as well as the nested segments of a Fermi surface pocket emerging from the cone. Our ARPES results show the close relationship of the Dirac cone to the charge-density-wave ordering, providing consistent explanations for exotic behaviors in this material.",
journal = "Physical Review B: Condensed Matter and Materials Physics",
title = "Observation of Dirac-like band dispersion in LaAgSb2",
volume = "93",
number = "8",
doi = "10.1103/PhysRevB.93.081105"
}

Shi, X., Richard, P., Wang, K., 
Liu, M., Matt, C. E., Xu, N., Dhaka, R. S., Ristić, Z., Qian, T., Yang, Y., Petrović, Č., Shi, M.,& Ding, H.. (2016). Observation of Dirac-like band dispersion in LaAgSb2. in Physical Review B: Condensed Matter and Materials Physics, 93(8).
https://doi.org/10.1103/PhysRevB.93.081105

Shi X, Richard P, Wang K, 
Liu M, Matt CE, Xu N, Dhaka RS, Ristić Z, Qian T, Yang Y, Petrović Č, Shi M, Ding H. Observation of Dirac-like band dispersion in LaAgSb2. in Physical Review B: Condensed Matter and Materials Physics. 2016;93(8).
doi:10.1103/PhysRevB.93.081105 .

Shi, Xun 
, Richard, Pierre, Wang, Kefeng, 
Liu, Mian , Matt, Christian Egon, Xu, N., Dhaka, Rajendra S., Ristić, Zoran, Qian, T., Yang, Yi-feng, Petrović, Čedomir, Shi, M., Ding, Hong, "Observation of Dirac-like band dispersion in LaAgSb2" in Physical Review B: Condensed Matter and Materials Physics, 93, no. 8 (2016),
https://doi.org/10.1103/PhysRevB.93.081105 . .

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  - Petrović, Čedomir
PY  - 2015
UR  - https://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 Petrović, Čedomir",
year = "2015",
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.,& Petrović, Č.. (2015). Local structure study of Fe dopants in Ni-deficit Ni3Al alloys. in 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, Petrović Č. Local structure study of Fe dopants in Ni-deficit Ni3Al alloys. in Journal of Alloys and Compounds. 2015;651:705-711.
doi:10.1016/j.jallcom.2015.08.171 .

Ivanovski, Valentin N., Umićević, Ana, Belošević-Čavor, Jelena, Lei, Hechang, Li, Lijun, Cekić, Božidar Đ., Koteski, Vasil J., Petrović, Čedomir, "Local structure study of Fe dopants in Ni-deficit Ni3Al alloys" in Journal of Alloys and Compounds, 651 (2015):705-711,
https://doi.org/10.1016/j.jallcom.2015.08.171 . .

TY  - JOUR
AU  - Lei, Hechang
AU  - Božin, Emil S.
AU  - Llobet, A.
AU  - Ivanovski, Valentin N.
AU  - Koteski, Vasil J.
AU  - Belošević-Čavor, Jelena
AU  - Cekić, Božidar Đ.
AU  - Petrović, Čedomir
PY  - 2012
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/5040
AB  - We report the evolution of structural and magnetic properties in La2O3(Fe1-xMnx)(2)Se-2. Heat capacity and bulk magnetization indicate an increased ferromagnetic component of the long-range magnetic order and possible increased degree of frustration. Atomic disorder on Fe(Mn) sites suppresses the temperature of the long-range order whereas intermediate alloys show a rich magnetic phase diagram.
T2  - Physical Review B: Condensed Matter and Materials Physics
T1  - Magnetism in La2O3(Fe1-xMnx)(2)Se-2 tuned by Fe/Mn ratio
VL  - 86
IS  - 12
DO  - 10.1103/PhysRevB.86.125122
ER  - 

@article{
author = "Lei, Hechang and Božin, Emil S. and Llobet, A. and Ivanovski, Valentin N. and Koteski, Vasil J. and Belošević-Čavor, Jelena and Cekić, Božidar Đ. and Petrović, Čedomir",
year = "2012",
abstract = "We report the evolution of structural and magnetic properties in La2O3(Fe1-xMnx)(2)Se-2. Heat capacity and bulk magnetization indicate an increased ferromagnetic component of the long-range magnetic order and possible increased degree of frustration. Atomic disorder on Fe(Mn) sites suppresses the temperature of the long-range order whereas intermediate alloys show a rich magnetic phase diagram.",
journal = "Physical Review B: Condensed Matter and Materials Physics",
title = "Magnetism in La2O3(Fe1-xMnx)(2)Se-2 tuned by Fe/Mn ratio",
volume = "86",
number = "12",
doi = "10.1103/PhysRevB.86.125122"
}

Lei, H., Božin, E. S., Llobet, A., Ivanovski, V. N., Koteski, V. J., Belošević-Čavor, J., Cekić, B. Đ.,& Petrović, Č.. (2012). Magnetism in La2O3(Fe1-xMnx)(2)Se-2 tuned by Fe/Mn ratio. in Physical Review B: Condensed Matter and Materials Physics, 86(12).
https://doi.org/10.1103/PhysRevB.86.125122

Lei H, Božin ES, Llobet A, Ivanovski VN, Koteski VJ, Belošević-Čavor J, Cekić BĐ, Petrović Č. Magnetism in La2O3(Fe1-xMnx)(2)Se-2 tuned by Fe/Mn ratio. in Physical Review B: Condensed Matter and Materials Physics. 2012;86(12).
doi:10.1103/PhysRevB.86.125122 .

Lei, Hechang, Božin, Emil S., Llobet, A., Ivanovski, Valentin N., Koteski, Vasil J., Belošević-Čavor, Jelena, Cekić, Božidar Đ., Petrović, Čedomir, "Magnetism in La2O3(Fe1-xMnx)(2)Se-2 tuned by Fe/Mn ratio" in Physical Review B: Condensed Matter and Materials Physics, 86, no. 12 (2012),
https://doi.org/10.1103/PhysRevB.86.125122 . .

TY  - JOUR
AU  - Cekić, Božidar Đ.
AU  - Umićević, Ana
AU  - Ivanovski, Valentin N.
AU  - Hu, Rongwei
AU  - Petrovic, Cedomir
AU  - David, Bohumil
AU  - Barudžija, Tanja
PY  - 2012
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4925
AB  - The perturbed angular correlation method was employed to study the temperature dependence of electric field gradients at the Ta-181 probe in the polycrystalline Hf2Ni7 compound. The temperature evolution of the sample content was measured using high-temperature X-ray diffraction. To check the magnetic order of the sample, magnetization measurements and additional perturbed angular correlation measurements with externally applied magnetic field were performed. All obtained spectra showed no evidence of magnetic order of the Hf2Ni7 phase. Within the experimental resolution of the apparatus, the measured electric field gradients at Ta-181 probe for the two inequivalent Hf-181/Ta-181 sites in the Hf2Ni7 compound appeared as one in the range of 78-944 K. A single quadrupole interaction implies that the electric field gradients at the two Hf sites must be quite similar. At 293 K, the measured quadrupole interaction parameters are v(Q) = 433(1) MHz and eta = 0.300(4). An increase of the quadrupole frequency and a gradual rising of the asymmetry parameter were observed with increasing temperature. The high-temperature X-ray diffraction indicated a build up of HfO2 above 693 K.
T2  - Nuclear technology and radiation protection
T1  - Perturbed Angular Correlation Investigation of the Electric Field Gradient At Ta-181 Probe in the Hf2ni7 Compound
VL  - 27
IS  - 2
SP  - 95
EP  - 102
DO  - 10.2298/NTRP1202095C
ER  - 

@article{
author = "Cekić, Božidar Đ. and Umićević, Ana and Ivanovski, Valentin N. and Hu, Rongwei and Petrovic, Cedomir and David, Bohumil and Barudžija, Tanja",
year = "2012",
abstract = "The perturbed angular correlation method was employed to study the temperature dependence of electric field gradients at the Ta-181 probe in the polycrystalline Hf2Ni7 compound. The temperature evolution of the sample content was measured using high-temperature X-ray diffraction. To check the magnetic order of the sample, magnetization measurements and additional perturbed angular correlation measurements with externally applied magnetic field were performed. All obtained spectra showed no evidence of magnetic order of the Hf2Ni7 phase. Within the experimental resolution of the apparatus, the measured electric field gradients at Ta-181 probe for the two inequivalent Hf-181/Ta-181 sites in the Hf2Ni7 compound appeared as one in the range of 78-944 K. A single quadrupole interaction implies that the electric field gradients at the two Hf sites must be quite similar. At 293 K, the measured quadrupole interaction parameters are v(Q) = 433(1) MHz and eta = 0.300(4). An increase of the quadrupole frequency and a gradual rising of the asymmetry parameter were observed with increasing temperature. The high-temperature X-ray diffraction indicated a build up of HfO2 above 693 K.",
journal = "Nuclear technology and radiation protection",
title = "Perturbed Angular Correlation Investigation of the Electric Field Gradient At Ta-181 Probe in the Hf2ni7 Compound",
volume = "27",
number = "2",
pages = "95-102",
doi = "10.2298/NTRP1202095C"
}

Cekić, B. Đ., Umićević, A., Ivanovski, V. N., Hu, R., Petrovic, C., David, B.,& Barudžija, T.. (2012). Perturbed Angular Correlation Investigation of the Electric Field Gradient At Ta-181 Probe in the Hf2ni7 Compound. in Nuclear technology and radiation protection, 27(2), 95-102.
https://doi.org/10.2298/NTRP1202095C

Cekić BĐ, Umićević A, Ivanovski VN, Hu R, Petrovic C, David B, Barudžija T. Perturbed Angular Correlation Investigation of the Electric Field Gradient At Ta-181 Probe in the Hf2ni7 Compound. in Nuclear technology and radiation protection. 2012;27(2):95-102.
doi:10.2298/NTRP1202095C .

Cekić, Božidar Đ., Umićević, Ana, Ivanovski, Valentin N., Hu, Rongwei, Petrovic, Cedomir, David, Bohumil, Barudžija, Tanja, "Perturbed Angular Correlation Investigation of the Electric Field Gradient At Ta-181 Probe in the Hf2ni7 Compound" in Nuclear technology and radiation protection, 27, no. 2 (2012):95-102,
https://doi.org/10.2298/NTRP1202095C . .

TY  - JOUR
AU  - Lei, Hechang
AU  - Ryu, Hyejin
AU  - Ivanovski, Valentin N.
AU  - Warren, J. B.
AU  - Frenkel, A. I.
AU  - Cekić, Božidar Đ.
AU  - Yin, Wei-Guo
AU  - Petrović, Čedomir
PY  - 2012
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/5176
AB  - We have successfully synthesized a layered iron oxychalcogenide BaFe2Se2O single crystal. This compound is built up of Ba and Fe-Se(O) layers alternatively stacked along the c axis. The Fe-Se(O) layers contain double chains of edge-shared Fe-Se(O) tetrahedra that propagate along the b axis and are bridged by oxygen along the a axis. Physical property measurements indicate that BaFe2Se2O is a semiconductor without the Curie-Weiss behavior up to 350 K. There is a possible long-range antiferromagnetic transition at 240 K, corresponding to the peak in specific-heat measurement, and two transitions at 115 K and 43 K where magnetic susceptibility drops abruptly. The magnetic entropy up to 300 K is much smaller than the expected value for Fe2+ in tetrahedral crystal fields and the Mossbauer spectrum indicates that long-range magnetic order is unlikely at 294 K. Our results suggest that BaFe2Se2O is a magnetic insulator at the borderline between a long-range antiferromagnetic spin ordering and possible spin dimerization.
T2  - Physical Review B: Condensed Matter and Materials Physics
T1  - Structure and physical properties of the layered iron oxychalcogenide BaFe2Se2O
VL  - 86
IS  - 19
DO  - 10.1103/PhysRevB.86.195133
ER  - 

@article{
author = "Lei, Hechang and Ryu, Hyejin and Ivanovski, Valentin N. and Warren, J. B. and Frenkel, A. I. and Cekić, Božidar Đ. and Yin, Wei-Guo and Petrović, Čedomir",
year = "2012",
abstract = "We have successfully synthesized a layered iron oxychalcogenide BaFe2Se2O single crystal. This compound is built up of Ba and Fe-Se(O) layers alternatively stacked along the c axis. The Fe-Se(O) layers contain double chains of edge-shared Fe-Se(O) tetrahedra that propagate along the b axis and are bridged by oxygen along the a axis. Physical property measurements indicate that BaFe2Se2O is a semiconductor without the Curie-Weiss behavior up to 350 K. There is a possible long-range antiferromagnetic transition at 240 K, corresponding to the peak in specific-heat measurement, and two transitions at 115 K and 43 K where magnetic susceptibility drops abruptly. The magnetic entropy up to 300 K is much smaller than the expected value for Fe2+ in tetrahedral crystal fields and the Mossbauer spectrum indicates that long-range magnetic order is unlikely at 294 K. Our results suggest that BaFe2Se2O is a magnetic insulator at the borderline between a long-range antiferromagnetic spin ordering and possible spin dimerization.",
journal = "Physical Review B: Condensed Matter and Materials Physics",
title = "Structure and physical properties of the layered iron oxychalcogenide BaFe2Se2O",
volume = "86",
number = "19",
doi = "10.1103/PhysRevB.86.195133"
}

Lei, H., Ryu, H., Ivanovski, V. N., Warren, J. B., Frenkel, A. I., Cekić, B. Đ., Yin, W.,& Petrović, Č.. (2012). Structure and physical properties of the layered iron oxychalcogenide BaFe2Se2O. in Physical Review B: Condensed Matter and Materials Physics, 86(19).
https://doi.org/10.1103/PhysRevB.86.195133

Lei H, Ryu H, Ivanovski VN, Warren JB, Frenkel AI, Cekić BĐ, Yin W, Petrović Č. Structure and physical properties of the layered iron oxychalcogenide BaFe2Se2O. in Physical Review B: Condensed Matter and Materials Physics. 2012;86(19).
doi:10.1103/PhysRevB.86.195133 .

Lei, Hechang, Ryu, Hyejin, Ivanovski, Valentin N., Warren, J. B., Frenkel, A. I., Cekić, Božidar Đ., Yin, Wei-Guo, Petrović, Čedomir, "Structure and physical properties of the layered iron oxychalcogenide BaFe2Se2O" in Physical Review B: Condensed Matter and Materials Physics, 86, no. 19 (2012),
https://doi.org/10.1103/PhysRevB.86.195133 . .

TY  - CONF
AU  - Cekić, Božidar Đ.
AU  - Umićević, Ana
AU  - Ivanovski, Valentin N.
AU  - Belošević-Čavor, Jelena
AU  - Koteski, Vasil J.
AU  - Hu, Rongwei
AU  - Petrović, Čedomir
PY  - 2010
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6992
AB  - The perturbed angular correlation method has been employed to study the temperature dependence of the Ta-181 hyperfine interaction parameters in the poly-crystalline intermetallic compound alpha HfNi. At ambient temperature the frequency of the electric quadrupole interaction was omega(Q) = 26.0(2) Mrad/s and the asymmetry parameter eta = 0.22(1). The magnitude of the observed electric field gradient decreases with increasing temperature from 78 to 900 K. The calculations were done using the augmented plane wave plus local orbitals method as implemented in the WIEN2k code, using the generalized gradient approximation. In addition, a supercell calculation with Ta impurity located at the hafnium site was performed. The obtained result is in a good agreement with the experiment.
C3  - Hyperfine Interactions
T1  - Thermal evolution of the electric field gradient at Ta-181 in alpha HfNi
VL  - 196
IS  - 1-3
SP  - 339
EP  - 347
DO  - 10.1007/s10751-009-0135-1
ER  - 

@conference{
author = "Cekić, Božidar Đ. and Umićević, Ana and Ivanovski, Valentin N. and Belošević-Čavor, Jelena and Koteski, Vasil J. and Hu, Rongwei and Petrović, Čedomir",
year = "2010",
abstract = "The perturbed angular correlation method has been employed to study the temperature dependence of the Ta-181 hyperfine interaction parameters in the poly-crystalline intermetallic compound alpha HfNi. At ambient temperature the frequency of the electric quadrupole interaction was omega(Q) = 26.0(2) Mrad/s and the asymmetry parameter eta = 0.22(1). The magnitude of the observed electric field gradient decreases with increasing temperature from 78 to 900 K. The calculations were done using the augmented plane wave plus local orbitals method as implemented in the WIEN2k code, using the generalized gradient approximation. In addition, a supercell calculation with Ta impurity located at the hafnium site was performed. The obtained result is in a good agreement with the experiment.",
journal = "Hyperfine Interactions",
title = "Thermal evolution of the electric field gradient at Ta-181 in alpha HfNi",
volume = "196",
number = "1-3",
pages = "339-347",
doi = "10.1007/s10751-009-0135-1"
}

Cekić, B. Đ., Umićević, A., Ivanovski, V. N., Belošević-Čavor, J., Koteski, V. J., Hu, R.,& Petrović, Č.. (2010). Thermal evolution of the electric field gradient at Ta-181 in alpha HfNi. in Hyperfine Interactions, 196(1-3), 339-347.
https://doi.org/10.1007/s10751-009-0135-1

Cekić BĐ, Umićević A, Ivanovski VN, Belošević-Čavor J, Koteski VJ, Hu R, Petrović Č. Thermal evolution of the electric field gradient at Ta-181 in alpha HfNi. in Hyperfine Interactions. 2010;196(1-3):339-347.
doi:10.1007/s10751-009-0135-1 .

Cekić, Božidar Đ., Umićević, Ana, Ivanovski, Valentin N., Belošević-Čavor, Jelena, Koteski, Vasil J., Hu, Rongwei, Petrović, Čedomir, "Thermal evolution of the electric field gradient at Ta-181 in alpha HfNi" in Hyperfine Interactions, 196, no. 1-3 (2010):339-347,
https://doi.org/10.1007/s10751-009-0135-1 . .

TY  - JOUR
AU  - Petrović, C
AU  - Lee, Y
AU  - Vogt, T
AU  - Lazarov, Nenad Đ.
AU  - Bud'ko, SL
AU  - Canfield, PC
PY  - 2005
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2912
AB  - The thermal expansion and heat capacity of FeSb2 at ambient pressure agrees with a picture of a temperature induced spin state transition within the Fe t(2g) multiplet. However, high pressure powder diffraction data show no sign of a structural phase transition up to 7 GPa. A bulk modulus B=84(3) GPa has been extracted and the temperature dependence of the Gruneisen parameter has been determined. We discuss here the relevance of a Kondo insulator description for this material.
T2  - Physical Review B: Condensed Matter and Materials Physics
T1  - Kondo insulator description of spin state transition in FeSb2
VL  - 72
IS  - 4
DO  - 10.1103/PhysRevB.72.045103
ER  - 

@article{
author = "Petrović, C and Lee, Y and Vogt, T and Lazarov, Nenad Đ. and Bud'ko, SL and Canfield, PC",
year = "2005",
abstract = "The thermal expansion and heat capacity of FeSb2 at ambient pressure agrees with a picture of a temperature induced spin state transition within the Fe t(2g) multiplet. However, high pressure powder diffraction data show no sign of a structural phase transition up to 7 GPa. A bulk modulus B=84(3) GPa has been extracted and the temperature dependence of the Gruneisen parameter has been determined. We discuss here the relevance of a Kondo insulator description for this material.",
journal = "Physical Review B: Condensed Matter and Materials Physics",
title = "Kondo insulator description of spin state transition in FeSb2",
volume = "72",
number = "4",
doi = "10.1103/PhysRevB.72.045103"
}

Petrović, C., Lee, Y., Vogt, T., Lazarov, N. Đ., Bud'ko, S.,& Canfield, P.. (2005). Kondo insulator description of spin state transition in FeSb2. in Physical Review B: Condensed Matter and Materials Physics, 72(4).
https://doi.org/10.1103/PhysRevB.72.045103

Petrović C, Lee Y, Vogt T, Lazarov NĐ, Bud'ko S, Canfield P. Kondo insulator description of spin state transition in FeSb2. in Physical Review B: Condensed Matter and Materials Physics. 2005;72(4).
doi:10.1103/PhysRevB.72.045103 .

Petrović, C, Lee, Y, Vogt, T, Lazarov, Nenad Đ., Bud'ko, SL, Canfield, PC, "Kondo insulator description of spin state transition in FeSb2" in Physical Review B: Condensed Matter and Materials Physics, 72, no. 4 (2005),
https://doi.org/10.1103/PhysRevB.72.045103 . .