Magnetic and transport properties of Ce3Au3-xPtxSb4

Lattice parameter, electrical resistivity rho, Hall constant R(H) and magnetic susceptibility chi have been measured for Ce3Au3-xPtxSb4 (x = 0.0, 0.5, 1.0, 1.5, 2.25, 3.0). It is found that the alloys for all x show semiconducting behavior. The magnetic susceptibilities for all x obey the Curie-Weiss law at high temperatures and the effective magnetic moments are close to the value for the free Ce3+ ion. The paramagnetic. Curie temperature increases with increasing x. From the results of the analysis based on a model of a mixture of Ce3+ and Ce4+ ions in Ce3Au3-xPtxSb4, it is revealed that the concentration of Ce4+ at low temperatures increase continuously with x and the paramagnetic Curie temperature is directly related to the activation energy between Ce4+ (J = 0) and Ce3+ (J = 5/2).