Magnetocaloric effect in the (Mn,Fe)2(P,Si) system

From bulk to nano

Journal article (2022)

Authors

F. Zhang RST/Fundamental Aspects of Materials and Energy - AS
Chris Taake Bielefeld University
B. Huang RST/Fundamental Aspects of Materials and Energy - AS
X. You RST/Fundamental Aspects of Materials and Energy - AS
Hamutu Ojiyed External organisation
Q. Shen RST/Fundamental Aspects of Materials and Energy - AS
A.I. Dugulan RID/TS/Instrumenten groep
Luana Caron Institute for Solar Fuels, Bielefeld University
N.H. van Dijk RST/Fundamental Aspects of Materials and Energy - AS
E.H. Brück RST/Fundamental Aspects of Materials and Energy - AS
Research Group
RST/Fundamental Aspects of Materials and Energy (AS) (TU Delft)
Copyright: © 2022 F. Zhang, Chris Taake, B. Huang, X. You, Hamutu Ojiyed, Q. Shen, A.I. Dugulan, Luana Caron, N.H. van Dijk, E.H. Brück
DOI: https://doi.org/10.1016/j.actamat.2021.117532
More Info
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Published Date

2022

Language

English

Faculty

Applied Sciences

Department

RST/Radiation, Science and Technology

Research Group

RST/Fundamental Aspects of Materials and Energy

Abstract

In the field of nanoscale magnetocaloric materials, novel concepts like micro-refrigerators, thermal switches, microfluidic pumps, energy harvesting devices and biomedical applications have been proposed. However, reports on nanoscale (Mn,Fe)2(P,Si)-based materials, which are one of the most promising bulk materials for solid-state magnetic refrigeration, are rare. In this study we have synthesized (Mn,Fe)2(P,Si)-based nanoparticles, and systematically investigated the influence of crystallite size and microstructure on the giant magnetocaloric effect. The results show that the decreased saturation magnetization (Ms) is mainly attributed to the increased concentration of an atomically disordered shell, and with a decreased particle size, both the thermal hysteresis and Tc are reduced. In addition, we determined an optimal temperature window for annealing after synthesis of 300–600 °C and found that gaseous nitriding can enhance Ms from 120 to 148 Am2kg−1 and the magnetic entropy change (ΔSm) from 0.8 to 1.2 Jkg−1K−1 in a field change of Δμ0H = 1 T. This improvement can be attributed to the synergetic effect of annealing and nitration, which effectively removes part of the defects inside the particles. The produced superparamagnetic particles have been probed by high-resolution transmission electron microscopy, Mössbauer spectra and magnetic measurements. Our results provide important insight into the performance of giant magnetocaloric materials at the nanoscale.