Superconductivity in epitaxial PtSb(0001) thin films

Abstract

Building on earlier reports of superconductivity in bulk PtSb, we present a systematic study of superconductivity in epitaxial PtSb(0001) thin films grown on SrF 2 ( 111 ) . Electrical transport measurements reveal a superconducting transition at T c = 1.72 K . The field-induced broadening of the transition and the temperature dependence of the upper critical fields are consistent with type-II superconductivity. We determine the upper critical fields for magnetic fields applied perpendicular and parallel to the film plane and parametrize their temperature dependence using an anisotropic Ginzburg-Landau approach. For a representative film in the intermediate thickness regime ( d = 50 n m ), we obtain coherence lengths of ξ a b ≈ 56 n m and ξ c ≈ 14 n m . Current-voltage characteristics show sizable critical currents, with a critical current density reaching J c ≈ 6 × 10 4 A / cm 2 at 0.5 K . These results establish the superconducting properties of epitaxial PtSb thin films and provide a basis for lattice-matched heterostructures within the NiAs-type materials family.