β Scribed by H. Nakamura; M. Machida; T. Koyama; N. Hamada
No coin nor oath required. For personal study only.
We perform first-principles calculations for anisotropy of various iron-based superconductors. The anisotropy ratio c k of the c-axis penetration depth to the ab-plane one is relatively small in BaFe 2 As 2 , LiFeAs and FeSe, indicating that the transport applications are promising in these superconductors. On the other hand, in those having perovskite-type blocking layers such as Sr 2 ScFePO 3 we find a very large value, c k J 200, comparable to that in strongly anisotropic high-T c cuprate Bi 2 Sr 2 CaCu 2 O 8Γd . Thus, the intrinsic Josephson junction stacks are expected to be formed along the c-axis, and novel Josephson effects due to the multi-gap nature are also suggested in these superconductors. We also examine the doping effect on the anisotropy of LaFeAsO.
π SIMILAR VOLUMES
We recently report that a superconducting transition is invoked by exposure to water vapor in undoped SrFe 2 As 2 , which occurs accompanied by shrinkage of the c-axis length of the unit cell. In this paper, we calculated structures and formation energies of O-/OH-related impurities and vacancies in