Physical metallurgy and magnetic behavior of Cd-stabilized b.c.c. β-Gd alloys

Abstract

The metallurgical and magnetic properties of Cd-stabilized b.c.c. β-Gd alloys were studied. The b.c.c. β-Gd phase could be retained at room temperature by alloying with Cd and liquid quenching. Single-phase alloys were obtained for Cd concentrations from 15 to 19 at.% Cd. Experimental data from these alloys were used to predict the physical properties of the pure b.c.c. Gd, such as the lattice parameter and the Curie temperature. Differential thermal analysis of the GdCd alloys revealed a two-step revision process on heating in which the b.c.c. alloy first transformed into an intermediate h.c.p. phase and then completely transformed to the equilibrium α-Gd + CdGd phases. The GdCd alloys exhibit a Gabay-Toulouse-type spin glass transition from a ferromagnetic state into a spin glass + ferromagnetic mixed state about 30 K. The occurrence of spin glass behavior at 81–85 at.% Gd is unique in that this is the highest concentration of a magnetic ion observed in a crystalline, metallic spin glass system.