REFRIGERANT CHARACTERISTICS OF R-AL AND R-SI AMORPHOUS-ALLOYS

R-Al and R-Si amorphous ribbon and powder samples were prepared by melt-quenching and mechanical grinding, respectively, in order to investigate the refrigerant characteristics. The magnetic transition temperature is selected without difficulty because the alloy composition in the amorphous state is not restricted by the stoichiometric composition. The magnetic entropy change of Dy-Al and R-Si amorphous alloys shows a broad maximum around the transition temperature, which is advantageous for a wide temperature span of refrigeration. The softening of those amorphous alloys below the crystallization temperature is useful for the purpose of static consolidation. The Debye temperature is increased by addition of B.