Anomalous behavior of the spin disorder resistivity of (La,RE)Sn3

Abstract

The temperature dependence of the spin disorder resistivity in dilute alloys of La1−xRExSn3 has been measured for RE=Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, and Er with x<0.10 and 1.5<T<300 K. The scaling of the high temperature incremental resistivity per rare-earth ion, Δρ/Δx, versus rare-earth atomic number is anomalous when compared to the variation typically seen in rare earth alloys and intermetallic systems. This quantity is larger for the lighter rare earths as compared to that measured for Gd and the heavier rare earths. For the lighter half of the RE series, the variation of the superconducting transition temperature depression rate ΔTs/Δx for (La,RE)Sn3 resembles the variation in Δρ/Δx. In addition, the temperature dependence of Δρ(T)/Δx for several rare-earth impurities is unusual. In particular, Δρ(T)/Δx for (La,Tb)Sn3 has a negative coefficient of resistivity at high temperatures with a maximum in the vicinity of 25 K. This anomalous temperature dependence can be accounted for by a first Born approximation calculation of the resistivity with the inclusion of both exchange and aspherical coulomb scattering in the presence of a crystalline electric field.