Enhanced reversibility of the magnetoelastic transition in (Mn,Fe)2(P,Si) alloys via minimizing the transition-induced elastic strain energy
Autor: | Ekkes Brück, Fengqi Zhang, Fengjiao Qian, Niels van Dijk, Yujing Zhang, Wenhui Guo, Yurong You, Feng Xu, Xuefei Miao, Yong Gong, Luana Caron, Yuanyuan Gong |
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Rok vydání: | 2022 |
Předmět: |
Phase transition
Materials science Polymers and Plastics Condensed matter physics (Mn Hysteresis Mechanical Engineering Transition temperature Magnetocaloric effect Neutron diffraction Metals and Alloys Elastic energy Si) Condensed Matter::Materials Science Ferromagnetism Mechanics of Materials Materials Chemistry Ceramics and Composites Magnetic refrigeration Density functional theory Fe)(2)(P |
Zdroj: | Journal of Materials Science & Technology. 103:165-176 |
ISSN: | 1005-0302 |
Popis: | Magnetocaloric materials undergoing reversible phase transitions are highly desirable for magnetic refrigeration applications. (Mn,Fe)(2)(P,Si) alloys exhibit a giant magnetocaloric effect accompanied by a magnetoelastic transition, while the noticeable irreversibility causes drastic degradation of the magnetocaloric properties during consecutive cooling cycles. In the present work, we performed a comprehensive study on the magnetoelastic transition of the (Mn,Fe)(2)(P,Si) alloys by high-resolution transmission electron microscopy, in situ field- and temperature-dependent neutron powder diffraction as well as density functional theory calculations (DFT). We found a generalized relationship between the thermal hysteresis and the transition-induced elastic strain energy for the (Mn,Fe)(2)(P,Si) family. The thermal hysteresis was greatly reduced from 11 to 1 K by a mere 4 at.% substitution of Fe by Mo in the Mn1.15Fe0.80P0.45Si0.55 alloy. This reduction is found to be due to a strong reduction in the transition-induced elastic strain energy. The significantly enhanced reversibility of the magnetoelastic transition leads to a remarkable improvement of the reversible magnetocaloric properties, compared to the parent alloy. Based on the DFT calculations and the neutron diffraction experiments, we also elucidated the underlying mechanism of the tunable transition temperature for the (Mn,Fe)(2)(P,Si) family, which can essentially be attributed to the strong competition between the covalent bonding and the ferromagnetic exchange coupling. The present work provides not only a new strategy to improve the reversibility of a first-order magnetic transition but also essential insight into the electron-spin-lattice coupling in giant magnetocaloric materials. (C) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology. |
Databáze: | OpenAIRE |
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