Low Temperature Resistivity, Magnetic Susceptibility, and Superconducting Transition Temperature in Lanthanum Containing Rare-Earth Impurities

Abstract

The resistivities and the magnetic susceptibilities of lanthanum containing small amounts of other rare-earth metals have been measured at low temperatures. Resistance minima have been found at about 6.5°K in fcc La-Ce alloys and at about 5.8°K in hcp La-Ce alloys. The temperature at which the resistance minimum occurs is independent of the concentration of Ce. Any minimum has not been found in the alloys with solutes other than Ce. The observed resistivity of all the alloys contains a term proportional to log T in accordance with the recent theories on the s - d or s - f resistivity due to Kondo and others. The magnetic susceptibilities of La-Ce, La-Pr, and La-Nd alloys are not inconsistent with the resistive behaviors of these alloys. The effective s - f exchange integrals for various rare-earth solutes have been calculated from the resistivity data and compared with those calculated from the change of the superconducting transition temperature of La due to added rare-earth metals. The agreement between...