Research output: Contribution to journal › Conference article › peer-review
The search for the new superconductors in the Ni-N system. / Gavryushkin, P. N.; Sagatov, N.; Sagatova, D. et al.
In: Journal of Physics: Conference Series, Vol. 1590, No. 1, 012010, 31.07.2020.Research output: Contribution to journal › Conference article › peer-review
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TY - JOUR
T1 - The search for the new superconductors in the Ni-N system
AU - Gavryushkin, P. N.
AU - Sagatov, N.
AU - Sagatova, D.
AU - Banaev, M. V.
AU - Donskikh, K. G.
AU - Litasov, K. D.
PY - 2020/7/31
Y1 - 2020/7/31
N2 - Transition metal nitrides show a unique combination of superconducting and mechanical properties. In this study we perform a theoretical search of the intermediate compounds in Ni-N system, determine their superconducting transition temperatures (Tc ) and bulk moduli (K 0) in the wide range of pressures, from 0 to 300 GPa. We have revealed several nickel-rich interstitial compounds, Ni5N2, Ni3N, and Ni6N, and one nitrogen-rich compound, NiN2, as stable structures. At pressures above 100 GPa, previously unknown NiN with anti-nickeline structure is also stabilized. All found compounds are non-magnetic. The most promising for superconductivity NiN2 structure is stable against decomposition on the mixture of (Ni+N) from 3 to at least 300 GPa. The transition from marcasite-type NiN2-Pnnm to pyrite-type NiN2-Pa3 occurs at 70 GPa. NiN2-Pnnm is an insulator with the band gap of about 1 eV, while NiN2-Pa3 is a metallic phase. The calculated Tc of NiN2-Pnnm equals to 10-2 K, and the bulk modulus (K 0) equals to 225 GPa at 10 GPa, which is in excellent agreement with available experimental data. The comparison of Tc of compounds in the Ni-H and Ni-N systems with that of the Fe-H and Fe-N compounds, shows that hydrides and nitrides of nickel have lower Tc than hydrides and nitrides of iron, which is explained by the significant differences in crystal structures.
AB - Transition metal nitrides show a unique combination of superconducting and mechanical properties. In this study we perform a theoretical search of the intermediate compounds in Ni-N system, determine their superconducting transition temperatures (Tc ) and bulk moduli (K 0) in the wide range of pressures, from 0 to 300 GPa. We have revealed several nickel-rich interstitial compounds, Ni5N2, Ni3N, and Ni6N, and one nitrogen-rich compound, NiN2, as stable structures. At pressures above 100 GPa, previously unknown NiN with anti-nickeline structure is also stabilized. All found compounds are non-magnetic. The most promising for superconductivity NiN2 structure is stable against decomposition on the mixture of (Ni+N) from 3 to at least 300 GPa. The transition from marcasite-type NiN2-Pnnm to pyrite-type NiN2-Pa3 occurs at 70 GPa. NiN2-Pnnm is an insulator with the band gap of about 1 eV, while NiN2-Pa3 is a metallic phase. The calculated Tc of NiN2-Pnnm equals to 10-2 K, and the bulk modulus (K 0) equals to 225 GPa at 10 GPa, which is in excellent agreement with available experimental data. The comparison of Tc of compounds in the Ni-H and Ni-N systems with that of the Fe-H and Fe-N compounds, shows that hydrides and nitrides of nickel have lower Tc than hydrides and nitrides of iron, which is explained by the significant differences in crystal structures.
UR - http://www.scopus.com/inward/record.url?scp=85090027639&partnerID=8YFLogxK
U2 - 10.1088/1742-6596/1590/1/012010
DO - 10.1088/1742-6596/1590/1/012010
M3 - Conference article
AN - SCOPUS:85090027639
VL - 1590
JO - Journal of Physics: Conference Series
JF - Journal of Physics: Conference Series
SN - 1742-6588
IS - 1
M1 - 012010
T2 - 32nd International Symposium on Superconductivity, ISS 2019
Y2 - 3 December 2019 through 5 December 2019
ER -
ID: 25299936