Impurity Scattering of the Conduction Electrons in Dysprosium Alloys

Abstract

The electrical resistivities of the intra-rare-earth alloys of dysprosium have been determined at 4.2°K, 77°K, and 296°K for a continued study of the impurity scattering of the conduction electrons. The resistivity data reveal that substitution of La, Ce, Pr, Nd, and Sm in Dy leads to considerable increases of the residual resistivity of Dy at low temperatures, but the increases disappear at 296°K. The impurity-induced resistivities Δρ0 are predominantly due to the exchange scattering of the electrons via the Ruderman-Kittel type exchange interaction between the 4f and conduction electrons. The exchange scattering is shown to depend only on the difference between the atomic spins of the solvent and solute ions, with the spin-orbit coupling playing an insignificant role. Since these features have also been observed in the Gd alloys, they are considered to be characteristic of the impurity scattering of the electrons in all rare-earth alloys. In the Dy alloys, however, the contribution to Δρ0 of the electrostatic scattering is much larger than that found in the Gd alloys. Also, at 77°K, the resistivities of the Dy alloys containing such solutes as Ce, Pr, and Nd show complex behavior, due probably to the formation of an antiferromagnetic spin structure.