Quaternary Ni-Mn-In-Y Heusler alloys: a way to achieve materials with better magnetocaloric properties?
Quaternary Ni-Mn-In-Y Heusler alloys: a way to achieve materials with better magnetocaloric properties?
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四元 Ni-Mn-In-Y Heusler 合金：一种获得具有更好磁热性能的材料的方法？
DOI：
10.1088/0022-3727/46/30/305003
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
M. Ogura and P. Entel
中科院分区：
文献类型：
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作者：
V. V. Sokolovskiy;V. D. Buchelnikov;S. V. Taskaev;V. V. Khovaylo;M. Ogura and P. Entel
采用从头算和Monte Carlo模拟方法研究了马氏体态铁磁和反铁磁耦合共存的Heusler合金Ni 50 Mn 34 In 16 Y中稀土杂质Y对磁热效应的影响.考虑不同的杂质配置。Mn子晶格上的Mn或Ni子晶格上的Ni被Y随机取代，或者取代可以同时发生在两个子晶格上。的磁性和磁热性能作为温度和磁场的函数，使用混合型的Potts和Blume-Emery-Griffiths模型，其中模型参数从从头计算获得。当改变杂质浓度时，由于复杂的竞争磁相互作用，在马氏体相变温度下磁化曲线的形状急剧改变。我们发现，如果Mn被Y取代，与Y取代Ni相比，反MCE效应增加。例如，合金系统Ni 50 Mn 32.75 Cu 1.25 In 16，其中5原子% Mn被Cu取代，表现出与Ni 50 Mn 34 In 16相比大两倍的逆MCE。这种预测模拟可用于设计显示较大MCE的Heusler复合材料。
The influence of nonmagnetic impurities (Y) on the magnetocaloric effect (MCE) in the Heusler alloy Ni 50 Mn 34 In 16 Y in which ferromagnetic and antiferromagnetic coupling coexists in the martensitic state is investigated by means of ab initio and Monte Carlo simulations. Different impurity configurations are considered. Either Mn on the Mn sublattice or Ni on the Ni sublattice is substituted randomly by Y or substitution may occur simultaneously on both sublattices. The magnetic and magnetocaloric properties are obtained as a function of temperature and magnetic field using a mixed type of Potts and Blume–Emery–Griffiths model where the model parameters are obtained from ab initio calculations. When varying the impurity concentration, the shape of the magnetization curves is drastically changed at the martensitic transformation temperature due to the complex competing magnetic interactions. We show that the inverse MCE effect increases if Mn is substituted by Y compared with Y substituting for Ni. For example, the alloy system Ni 50 Mn 32.75 Cu 1.25 In 16 where 5 at% Mn is replaced by Cu exhibits an inverse MCE which is twice as large compared with Ni 50 Mn 34 In 16. Such predictive simulations may be used to design Heusler composites which display larger MCEs.