Method of making an active magnetic refrigerant represented by Gd5(SixGe1−x)4alloy for 0≦x≦1.0 comprising placing amounts of the commercially pure Gd, Si,and Ge charge components in a crucible, heating the charge contents under subambient pressure to a melting temperature of the alloy for a time sufficient to homogenize the alloy and oxidize carbon with oxygen present in the Gd charge component to reduce carbon, rapidly solidifying the alloy in the crucible, and heat treating the solidified alloy at a temperature below the melting temperature for a time effective to homogenize a microstructure of the solidified material, and then cooling sufficiently fast to prevent the eutectoid decomposition and improve magnetocaloric and/or the magnetostrictive and/or the magnetoresistive properties thereof.
US 6,589,366 B1
Iowa State University Research Foundation, Inc.
Gschneidner, Karl A. Jr.; Pecharsky, Alexandra O.; and Pecharsky, Vitalij K., "Method of making active magnetic refrigerant, colossal magnetostriction and giant magnetoresistive materials based on Gd-Si-Ge alloys" (2003). Iowa State University Patents. 289.