Critical pressure effects in PdNi alloys

Abstract

The magnetic properties such as Curie temperatures, spontaneous magnetizations, paramagnetic susceptibilities and their pressure derivatives of PdNi alloys with nickel concentrations below 15% have been measured. All these properties (from our measurements as well from previously published measured values for nickel concentrations up to 40%) are well described in a local model of coupling between nickel moments through the palladium matrix. From the concentration dependence of the Curie temperature and its pressure variation the authors derived values for the exchange integral between localized moments and d electrons and for its pressure derivative in agreement with values found in the case of PdFe and PdCo alloys. The paramagnetic susceptibilities follow a Curie-Weiss law. There exist concentration ranges where the spontaneous magnetization as well as its pressure derivative vary proportionally to the concentration.