Superconducting parameters of BaPt4-xAuxGe12 filled skutterudite

Article

关键词: MUON-SPIN-ROTATION;    II SUPERCONDUCTORS;    PENETRATION DEPTH;    MAGNETIC-FIELD;    VORTEX STATE;    TC;    TEMPERATURE;    LAFE4P12;    LATTICES;    DENSITY;   

DOI  :  10.1103/PhysRevB.86.174513

来源: SCIE

【 摘 要 】

We report on a study of the superconducting properties for a series of polycrystalline BaPt4-xAuxGe12 filled skutterudite compounds for x = 0, 0.5, 0.75, and 1. Muon spin rotation (mu SR) spectroscopy as well as magnetization, specific-heat, and electrical resistivity measurements were performed. The magnetic penetration depth lambda, the coherence length xi, and the Ginzburg-Landau parameter kappa are evaluated. The temperature dependence of the superfluid density is well described by an s-wave superconducting gap and this classical scenario is supported by the field-independent lambda. The gap-to-T-c ratio Delta(0)/k(B)T(c) increases with the Au content from 1.70 for x = 0 to 2.1(1) for x = 1. By combining mu SR, magnetization, and specific-heat data, we find that BaPt4-xAuxGe12 compounds are in between the dirty and clean limits with mean free paths of the carriers l similar to xi. Interestingly, resistivity data for BaPt4Ge12 indicate a much higher upper critical field, which is probably due to defects or impurities close to the surface of the crystallites.

【 授权许可】

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