EQUIATOMIC TERNARY LANTHANUM-TRANSITION METAL-TIN PHASES - STRUCTURALAND ELECTRICAL RESULTS

The crystallographic parameters and electrical resistivity measurement s 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 incr easing group number of the transition metal is observed. A new superco nducting compound, LaRhSn with T-c=1.7 K, is detected by electrical re sistivity measurements and confirmed by a.c. susceptibility data. A ne gative curvature in the thermal dependence of the electrical resistivi ty is observed for all compounds. A quantitative analysis of the exper imental data using Mott's model and the phenomenological exponential a pproach is reported.