Electronic properties of PuNi3-type intermetallic superconductor LaRh3.

• A detailed study of the physical properties of the intermetallic superconductor LaRh3 was presented. • A much lower zero-temperature upper critical field is found for LaRh3, in sharp contrast to that of the isostructural LaIr3. • LaRh3 was categorized as a weak-coupling BCS superconductor with an isotropic s-wave gap. Electrical resistivity, magnetic susceptibility, and heat capacity of the intermetallic superconductor LaRh 3 are systematically studied. LaRh 3 crystallizes in the PuNi 3 -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 LaRh 3 is a type-II superconductor. The estimated zero-temperature upper critical field μ 0 H c 2 (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 LaRh 3 is a weak-coupling BCS superconductor with an isotropic s -wave gap. [ABSTRACT FROM AUTHOR]