Lower critical fields of superconducting PrFeAsO1-y single crystals
Lower critical fields of superconducting PrFeAsO1-y single crystals
复制标题
DOI：
10.1103/physrevb.79.064520
复制
发表时间：
2009-02-01
影响因子：
3.7
通讯作者：
Matsuda, Y.
中科院分区：
文献类型：
--
作者：
Okazaki, R.;Konczykowski, M.;Matsuda, Y.
We have studied the lower critical fields H-c1 of superconducting iron oxipnictide PrFeAsO1-y single crystals for H parallel and perpendicular to the ab planes. Measurements of the local magnetic induction at positions straddling the sample edge by using a miniature Hall-sensor array clearly resolve the first flux penetration from the Meissner state. The temperature dependence of H-c1 for H parallel to c is well scaled by the in-plane penetration depth without showing any unusual behavior, in contrast to previous reports. The anisotropy of penetration lengths at low temperatures is estimated to be similar or equal to 2.5, which is considerably smaller than the anisotropy of the coherence lengths. This is indicative of multiband superconductivity in this system in which the active band for superconductivity is more anisotropic. We also point out that the local induction measured at a position near the center of the crystal, which has been used in a number of reports for the determination of H-c1, might seriously overestimate the obtained H-c1 value.
