1. First-principles study on iron-pnictide superconductors Ca(Fe1−xCox)2As2
- Author
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Jun Yang, Qilin Zhang, Chunhui Fan, Dan Cai, Li-an Chen, Rende Miao, Liang Wang, Xuan Chen, and Zhong Bai
- Subjects
Coupling constant ,Superconductivity ,Materials science ,Condensed matter physics ,Phonon ,chemistry.chemical_element ,General Chemistry ,Electronic structure ,Manganese ,Condensed Matter Physics ,Tetragonal crystal system ,chemistry ,Phase (matter) ,Materials Chemistry ,Pnictogen - Abstract
The electronic structure, lattice dynamics, and electron–phonon ( e– ph) coupling constants λ for the superconducting Ca(Fe 1− x Co x ) 2 As 2 ( x =0.075, 0.1) are obtained by first-principles nonmagnetic calculations using norm-conserving pseudopotentials within virtual–crystal approximation treatment. Combined with the e– ph coupling constant λ for vicinity of collapsed tetragonal phase of CaFe 2 As 2 , we show that although the obtained λ cannot account for the high superconducting transition temperatures T C , they are almost a factor of two larger than that estimated in early calculations for that of vicinity of collapsed tetragonal phase of CaFe 2 As 2 . We confirm that superconductivity in Ca(Fe 1− x Co x ) 2 As 2 is not primarily phonon mediated. Nevertheless, the e– ph interactions are strong enough to be not negligible to investigate the superconductivity. Furthermore, we conjecture that Ca(Fe 1− x Mn x ) 2 As 2 or CaMn 2 As 2 serial compounds may be potential new e– ph superconductors or unconventional manganese pnictide superconductors. more...
- Published
- 2013
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