Superconductivity in intermetallic compound Mo₇Re₁₃X(X = B,C)

We report here the physical properties of a new intermetallic superconductor Mo7Re13X(X = B,C) (Tc = 8.3 K (X = B) and 8.1 K (X = C)). The crystal structure of Mo7Re13X is the β-Mn-type (cubic, space group: P4132) and the Re atoms form a tilted octahedron. The magnetization (M–H) curves show a typical type-II superconductivity; the lower critical field Hc1(0), upper critical field Hc2(0) and Ginzburg–Landau (GL) parameter value κ are, respectively, 3.0 Oe, 15.4 T and 101 for X = B and 3.1 Oe, 14.8 T and 98 for X = C. The superconducting gap versus kBTc:2Δ/kBTc values are 4.4 for X = B and 4.2 for X = C, which implies that superconductivity in Mo7Re13X(X = B,C) can be described by an s-wave strong coupling regime.