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Письма в Журнал экспериментальной и теоретической физики, 2010, том 91, выпуск 10, страницы 567–571
(Mi jetpl722)
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Эта публикация цитируется в 42 научных статьях (всего в 42 статьях)
КОНДЕНСИРОВАННЫЕ СРЕДЫ
Anion height dependence of T$_c$ and density of states in iron based superconductors
E. Z. Kuchinskii, I. A. Nekrasov, M. V. Sadovskii Institute of Electrophysics RAS, Urals Branch
Аннотация:
Systematic ab initio LDA calculations were performed for all the typical representatives of recently discovered class of iron based high-temperature superconductors: REOFe(As,P) (RE=La,Ce,Nd,Sm,Tb), Ba$_2$Fe$_2$As, (Sr,Ca)FFeAs, Sr$_4$Sc$_2$O$_6$Fe$_2$P$_2$, LiFeAs and Fe(Se,Te). Non-monotonic behavior of total density of states at the Fermi level is observed as a function of anion height relative to Fe layer with maximum at about $\Delta z_a\sim$1.37Å, attributed to changing Fe – As (P,Se,Te) hybridization. This leads to a similar dependence of superconducting transition temperature $T_c$ as observed in the experiments. The fit of this dependence to elementary BCS theory produces semiquantitative agreement with experimental data for $T_c$ for the whole class of iron based superconductors. The similar fit to Allen–Dynes formula underestimates $T_c$ in the vicinity of the maximum, signifying the possible importance of non – phonon pairing in this region. These results unambiguously demonstrate that the main effect of $T_c$ variation between different types of iron based superconductors is due to the corresponding variation of the density of states at the Fermi level.
Поступила в редакцию: 07.04.2010
Образец цитирования:
E. Z. Kuchinskii, I. A. Nekrasov, M. V. Sadovskii, “Anion height dependence of T$_c$ and density of states in iron based superconductors”, Письма в ЖЭТФ, 91:10 (2010), 567–571; JETP Letters, 91:10 (2010), 518–522
Образцы ссылок на эту страницу:
https://www.mathnet.ru/rus/jetpl722 https://www.mathnet.ru/rus/jetpl/v91/i10/p567
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