Electronic properties of PuNi3-type intermetallic superconductor LaRh3

Abstract Electrical resistivity, magnetic susceptibility, and heat capacity of the intermetallic superconductor LaRh3 are systematically studied. LaRh3 crystallizes in the PuNi3-type rhombohedral structure, which displays a sharp superconducting transition at temperature  ≈ 2.6 K on both the electrical resistivity and magnetic susceptibility curves. The magnetization hysteresis loop indicates that LaRh3 is a type-II superconductor. The estimated zero-temperature upper critical field μ0Hc2(0) is around 0.8 T, which locates far below the Pauli limit, indicating possible conventional superconductivity. Further analysis on the heat capacity data reveals that LaRh3 is a weak-coupling BCS superconductor with an isotropic s-wave gap.