Tuning structural-transformation temperature toward giant magnetocaloric effect in MnCoGe alloy: A theoretical study
Tuning structural-transformation temperature toward giant magnetocaloric effect in MnCoGe alloy: A theoretical study
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DOI：
10.1016/j.jallcom.2020.157063
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发表时间：
2021-02
影响因子：
6.2
通讯作者：
Hung Ba Tran;T. Fukushima;Kazunori Sato;Y. Makino;T. Oguchi
中科院分区：
文献类型：
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作者：
Hung Ba Tran;T. Fukushima;Kazunori Sato;Y. Makino;T. Oguchi
我们提出了一个新的模型和方案来考虑Mn 1-xCuxCoGe的结构转变对磁热性能的影响。磁交换耦合常数估计从第一性原理计算的基础上密度泛函理论。利用平均场近似半定量地再现了磁相图。用修正的Potts模型较好地再现了Mn 0.89Cu 0.11CoGe合金的巨等温磁熵变与磁结构耦合。磁结构耦合对等温磁熵变的增强作用强烈依赖于正交相和六方相的磁相变温度。
We propose a new model and scheme to consider the effect of structural transformation on magnetocaloric properties of Mn1-xCuxCoGe. The magnetic exchange coupling constants are estimated from first-principles calculations based on density functional theory. The magnetic phase diagram is semi-quantitatively reproduced by using mean-field approximation. The giant isothermal magnetic entropy change with the magnetostructural coupling of Mn0.89Cu0.11CoGe alloy is well reproduced by using the modified Potts model. The enhancement of magnetostructural coupling on the isothermal magnetic entropy change strongly depends on the condition of the magnetic phase transition temperature of orthorhombic and hexagonal phases.