Equiatomic ternary lanthanum-transition metal-tin phases: Structural and electrical results

The crystallographic parameters and electrical resistivity measurements in the 1.5-300 K temperature range for the LaXSn phases (X = Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au) are reported. A change in structure with increasing group number of the transition metal is observed. A new superconducting compound, LaRhSn with T-c=1.7 K, is detected by electrical resistivity measurements and confirmed by a.c. susceptibility data. A negative curvature in the thermal dependence of the electrical resistivity is observed for all compounds. A quantitative analysis of the experimental data using Mott's model and the phenomenological exponential approach is reported.