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Reduction of Large Hysteresis Losses in the Gd5uGe2uSi2u Magnetic Refrigerant Compound by a Small Alloying Addition of Iron



Virgil Provenzano, Alexander J. Shapiro, Robert D. Shull


This paper describes the discovery of an effective and straightforward method for reducing (by more than 90 percent) the large hysteresis losses observed in the Gd5Ge2Si2 magnetic refrigerant compound in the 270 K-300 K temperature range. These are the same temperatures where the compound exhibits its large ( giant according to some scientists) magnetocaloric effects. Before this material can be effectively used as a magnetic refrigerant, its large hysteretic losses need to be significantly reduced. Our method for accomplishing this reduction consists of alloying the Gd5Ge2Si2 compound with a small amount of iron. The magnetic entropy change, Sm, of the iron-containing alloy also attains a peak value at a higher temperature, 305 K, than the 275 K value for Gd5Ge2Si2, and its peak width is greater for the iron-containing material. A refrigeration capacity figure of merit clearly shows that the iron-containing alloy is superior for near-room temperature magnetic refrigeration.


alloy, hysteresis, magnetic entropy, magnetic refrigerant compound


Provenzano, V. , Shapiro, A. and Shull, R. (2004), Reduction of Large Hysteresis Losses in the Gd<sub>5</sub>uGe<sub>2</sub>uSi<sub>2</sub>u Magnetic Refrigerant Compound by a Small Alloying Addition of Iron, Nature, [online], (Accessed April 22, 2024)
Created June 24, 2004, Updated February 17, 2017