US Patent 7651574 Doped Gd

A Gd5Ge2Si2 refrigerant compound is doped or alloyed with an effective amount of silicide-forming metal element such that the magnetic hysteresis losses in the doped Gd5Ge2Si2 compound are substantially reduced in comparison to the hysteresis losses of the undoped Gd5Ge2Si2 compound. The hysteresis losses can be nearly eliminated by doping the Gd5Ge2Si2 compound with iron, cobalt, manganese, copper, or gallium. The effective refrigeration capacities of the doped Gd5Ge2Si2 compound are significantly higher than for the undoped Gd5Ge2Si2 compound.