Enhanced magnetocaloric properties of annealed melt-extracted Mn1.3Fe0.6P0.5Si0.5 microwires

Description

: The highly regarded Fe2P-based magnetocaloric materials are usually fabricated by ball milling, and require an additional extended annealing treatment at high temperatures (at temperatures up to 1423 K for several hours to days). In this work, we show that fabricating Mn1.3Fe0.6P0.5Si0.5 into the form of microwires attained 82.1 wt.% of the desired Fe2P phase in the as-cast state. The microwires show a variable solidification structure along the radial direction; close to the copper wheel contact, Fe2P phase is in fine grains, followed by dendritic Fe2P grains and finally secondary (Mn,Fe)5Si3 phase in addition to the dendritic Fe2P grains. The as-cast microwires undergo a ferroto para-magnetic transition with a Curie temperature of 138 K, showing a maximum isothermal magnetic entropy change of 4.6 J kg−1 K −1 for a magnetic field change of 5 T. With further annealing, a two-fold increase in the maximum isothermal magnetic entropy change is found in the annealed microwires, which reveal 88.1 wt.% of Fe2P phase.

Abstract

National Natural Science Foundation de China - NSFC 51871124

Abstract

Ministerio de Ciencia e Innovación y Agencia Estatal de Investigación, de España MCIN/AEI - PID2019-105720RB-I00

Abstract

Consejería de Economía, Conocimiento, Empresas y Universidad de la Junta de Andalucía - P18-RT-746

Abstract

China Scholarship Council - CSC 202006120203

Additional details