Title: Effect of particles size on the magnetocaloric properties in Gd₅Si₂Ge₂

Authors: LiQiang Zhang; Hong Zeng

Addresses: College of Mechanical and Electrical Engineering, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China ' Advance Technology & Materials Co., Ltd., China Iron & Steel Research Institute Group, Beijing 100081, China

Abstract: In this study, the effect of particle size on the magneto-thermal properties of Gd₅Si₂Ge₂ alloys was investigated. It is found that the alloy powders obtained via the milled processing conditions possess distinctly Magnetocaloric Effects (MCEs). The magnetic entropy change (ΔS_M) of the milled Gd₅Si₂Ge₂ alloy powders for the 38.5-50 um arrives the maximum value of -ΔS_M = 9.06 J•kg⁻¹•K⁻¹ for magnetic field change under 2.0 Tesla. The estimated Relative Cooling Power (RCP) for the 50-74 um powders is around 155.94 J kg⁻¹, which increases 28% comparing with that of the as-cast alloy (121.67 J kg⁻¹). These results indicate that the particle size in the micrometre range can remarkably affect the MCE in the alloys, and consequently, strong influence on the conversion performance. Therefore, care should be taken to choose the appropriate particle size for the magnetic refrigerant materials.

Keywords: magnetocaloric effect; RCP; relative cooling power; particle sizes; Gd5Si2Ge2 alloys; gadolinium silicon germanium alloys; magnetic refrigerant materials; microstructure; materials properties.

DOI: 10.1504/IJMMP.2013.057069

International Journal of Microstructure and Materials Properties, 2013 Vol.8 No.4/5, pp.325 - 332

Published online: 07 Oct 2013 *

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