A Gd.sub.5Ge.sub.2Si.sub.2 refrigerant compound is doped or alloyed with an effective amount of silicide-forming metal element such that the magnetic hysteresis losses in the doped Gd.sub.5Ge.sub.2Si.sub.2 compound are substantially reduced in comparison to the hysteresis losses of the undoped Gd.sub.5Ge.sub.2Si.sub.2 compound. The hysteresis losses can be nearly eliminated by doping the Gd.sub.5Ge.sub.2Si.sub.2 compound with iron, cobalt, manganese, copper, or gallium. The effective refrigeration capacities of the doped Gd.sub.5Ge.sub.2Si.sub.2 compound are significantly higher than for the undoped Gd.sub.5Ge.sub.2Si.sub.2 compound.