The magnetic properties of high-purity ZrZn2in pulsed fields of up to 17 T

Abstract

Measurements of the specific magnetisation, sigma , of high-purity samples of the weak ferromagnetic ZrZn₂ in the temperature range 2.5-270K and in pulsed magnetic fields of up to 17 T are presented. The data indicate that ferromagnetism is an intrinsic property of ZrZn₂ and are consistent, below the ordering temperature with the Stoner-Wohlfarth model of very weak itinerant ferromagnetism. The Curie temperature, T_c, is higher than that previously measured with the same samples (27K compared with 21K). It is estimated that T_c increases significantly with thermal expansion in the paramagnetic region but is accompanied by a decrease in the 0K susceptibility chi ₀; thus the prediction of the Stoner-Wohlfarth model of a linear dependence of chi ^-1 on T² is retained. The observed Curie-Weiss temperature dependence in conjunction with the parallel nature of the sigma ² against H/ sigma isotherms is thus inconsistent with this model.