Superconductivity in epitaxial PtSb(0001) thin films

TL;DR

This paper reports the discovery of superconductivity in epitaxial PtSb(0001) thin films grown on SrF2(111), with a transition temperature of 1.72 K, and characterizes their superconducting properties including critical fields and currents.

Contribution

It is the first demonstration of superconductivity in epitaxial PtSb thin films, expanding the family of NiAs-type superconducting materials and providing a platform for heterostructure integration.

Findings

Superconducting transition at 1.72 K in PtSb(0001) films.

Type-II superconductivity confirmed by critical field measurements.

Critical current density reaches 6×10^4 A/cm^2 at 0.5 K.

Abstract

We report superconductivity in epitaxial PtSb(0001) thin films grown on SrF2(111). Electrical transport measurements reveal a superconducting transition at $T_{\mathrm c}=1.72$ K. The field-induced broadening of the transition and the presence of finite upper critical fields are consistent with type-II superconductivity. We determine the resistively defined upper critical fields for magnetic fields applied perpendicular and parallel to the film plane and parameterize their temperature dependence using an anisotropic Ginzburg-Landau approach. For the thickest film ($d=50$ nm), this yields coherence lengths of $\xi_{ab}\approx 55$ nm and $\xi_c\approx 14$ nm. Current-voltage characteristics show sizeable critical currents, with a critical current density reaching $J_{\mathrm c}\approx 6e4$ A/cm$^2$ at 0.5 K. These results establish epitaxial PtSb as a superconducting thin-film platform compatible with lattice-matched heterostructures in the NiAs-type materials family.