Non-linear susceptibility and ferromagnetic-like scaling in random magnetic anisotropy alloys

Abstract

We report on the critical behaviour of amorphous (Gd 1− x Tb x ) 2Cu random magnetic anisotropy (RMA) systems. The magnetisation data show ferromagnetic-like scaling, with exponents indicating a crossover, when x increases, from coherent spin-glass (CSG) to spin-glass (SG) character at low fields and from ferromagnet to ferromagnet of wandering axis at high fields. Scaling of the non-linear susceptibility yield exponents akin to another RMA spin glasses, suggesting that the present systems undergo a SG phase transition in zero field.