PHYSICAL METALLURGY AND MAGNETIC-BEHAVIOR OF CD-STABILIZED BCC BETA-GD ALLOYS

The metallurgical and magnetic properties of Cd-stabilized b.c.c. beta -Gd alloys were studied. The b.c.c. beta-Gd phase could be retained at room temperature by alloying with Cd and liquid quenching. Single-pha se alloys were obtained for Cd concentrations from 15 to 19 at.% Cd. E xperimental data from these alloys were used to predict the physical p roperties 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. al loy first transformed into an intermediate h.c.p. phase and then compl etely transformed to the equilibrium alpha-Gd + CdGd phases. The Gd-Cd alloys exhibit a Gabay-Toulouse-type spin glass transition from a fer romagnetic state into a spin glass + ferromagnetic mixed state about 3 0 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 i n a crystalline, metallic spin glass system.