Method of making active magnetic refrigerant, colossal magnetostriction and giant magnetoresistive materials based on Gd-Si-Ge alloys

Method of making a material represented by R5 (SixGe1−x)4 where 0≦x≦1.0, and where R is one or a combination of rare earth elements selected from the group consisting of Gd, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu, comprising:

• a) placing amounts of R, Si, and Ge as charge components in a crucible,
• b) heating the charge components under subambient pressure to form a melt and to reduce an amount of an interstitial element present in the charge component comprising R, and
• c) solidifying the melt to provide solidified material.

A method of making a material represented by R5(SixGe1−x)4 where R is one or a combination of rare earth elements selected from the group of Gd, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu, 0≦x≦1.0, comprising heat treating solidified R5(SixGe1−x)4 material at a temperature for a time to increase a magnetocaloric property.

Method of making a material represented by R5 (SixGe1−x)4 alloy, where R is one or a combination of rare earth elements selected from the group consisting of Gd, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and where 0≦x≦1.0 comprising:

• a) placing amounts of R, Si, and Ge as charge components in a crucible,
• b) heating the charge components under subambient pressure to form a melt, and
• c) solidifying the melt to provide solidified material.

In a multi-stage magnetic refrigerator, the combination of a first stage comprising Gd5(SixGe1−x)4 material where 0.5<x≦1.0, and a second stage comprising a different material.

In a multi-layered regenerator bed, the combination of a first layer comprising Gd5 (SixGe1−x)4 material where 0.5<x≦1.0, and a second layer comprising a different material.