Superconducting properties of CeIr3 single crystal with rhombohedral structure were examined for the first time using DC magnetization, specific heat, and electrical resistivity measurements. A bulk type-II superconductivity was clearly detected at Tc = 3.4K, which is the second highest Tc among Ce-based intermetallic compounds. The thermodynamic properties as well as an upper critical field Hc2(0) ∼ 46.5kOe for the H ∥ c-axis are fully consistent with the weak-coupling BCS regime. The observed pffiffiffiffi H variation of C(H)=T becomes less pronounced upon cooling, possibly suggesting a suppression of low-energy quasiparticle excitations in an anisotropic s-wave gap in CeIr3, as observed in CeRu2. The origin of superconductivity is discussed from the viewpoints of the valence of Ce atom and Ir 5d-electron with a strong spin–orbit coupling.
ASJC Scopus subject areas
- Physics and Astronomy(all)