Single Crystal Growth and Anisotropic Superconducting Property of PuRhGa₅

Abstract

We grew a single crystal of the transuranium superconductor PuRhGa 5 with the tetragonal structure by the Ga-flux method, and measured its magnetic susceptibility, magnetization and AC susceptibility. The magnetic susceptibility is found to reveal no distinct anisotropy between H ∥[100] and [001]. The upper critical field H c2 for superconductivity is, however, highly anisotropic: H c2 (0) = 270 kOe for H ∥[100] and 150 kOe for H ∥[001]. The angular dependence of H c2 is well fitted by the anisotropic mass model, reflecting a quasi-two-dimensional electronic state. The Maki parameter κ 2 and thermodynamical critical field H c are approximately determined as κ 2 ≃50 and H c (0) = 4.7 kOe from the equilibrium magnetization curve.