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, Tc, is higher than that previously measured with the same samples (27K compared with 21K). It is estimated that Tc 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.