Publication Date

7-2-2019

Department

Ames Laboratory; Materials Science and Engineering

Campus Units

Materials Science and Engineering, Ames Laboratory

OSTI ID+

1556924

Report Number

IS-J 9989

DOI

10.1007/s11837-019-03626-1

Journal Title

JOM: Journal of the Minerals, Metals and Materials Society

Volume Number

71

Issue Number

9

First Page

3159

Last Page

3163

Abstract

Materials exhibiting a large magnetocaloric effect (MCE) at or near room temperature are critical for solid-state refrigeration applications. The MCE is described by a change in entropy (ΔSM) and/or temperature (ΔTad) of a material in response to a change in applied magnetic field. Ball milled materials generally exhibit smaller ΔSM values compared to bulk; however, milling broadens the effect, potentially increasing the relative cooling power (RCP). The as-cast Gd5Si4 is an attractive option due to its magnetic transition at 340 K and associated MCE. Investigation of effect of particles size and transition temperature in the binary material, Gd5Si4, can lead to development of functionally graded bulk material with higher MCE and RCP than the traditional bulk materials. A two-step ball-milling process, in which coarse powder of Gd5Si4 was first milled with poly(ethylene glycol) followed by milling in heptane was used to produce fine particles of Gd5Si4 that showed a broad distribution in particle size. Magnetic measurement on the milled sample obtained after washing with water show a decrease in Curie temperature and significant broadening of the magnetic transition. Compared to bulk Gd5Si4, the maximum MCE of the milled samples is also reduced and shifted down by close to 30 K, but the MCE remains substantial over a broader temperature range. The RCP of both milled samples increased 75% from the bulk material.

DOE Contract Number(s)

AC02-07CH11358; 1726617; 1357565

Language

en

Department of Energy Subject Categories

36 MATERIALS SCIENCE

Publisher

Iowa State University Digital Repository, Ames IA (United States)

Available for download on Thursday, July 02, 2020

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