ABSTRACT

We report a study of the metamagnetic transition and magnetocaloric effect in the ternary Ni₄₅Mn₄₂In₁₃ Heusler alloy system. We also investigate the structural and magnetic properties of the alloy. The crystal structure exhibited a mixture phase of martensite and austenite at room temperature which are typical for Heusler alloys. The thermomagnetization curves have martensitic and magnetic transition near room temperature and with a quite large magnetization value under 5 T applied external magnetic field. The obvious reversible metamagnetic behavior was seen between 285 and 295 K temperatures. The isothermal M–H curves also confirmed the metamagnetic transition and provided the magnetocaloric effects by Maxwell relations. This system underwent an austenite–martensite phase transition and the change in magnetic entropy was found to be quite large across this martensitic transition, so this led to an inverse magnetocaloric effect. Significant maximum magnetic entropy was obtained under 5 T applied magnetic field.

摘要

我们报告了三元 Ni ₄₅ Mn ₄₂ In ₁₃中的变磁转变和磁热效应的研究赫斯勒合金系统。我们还研究了合金的结构和磁性。晶体结构在室温下呈现马氏体和奥氏体的混合相，这是 Heusler 合金的典型特征。热磁化曲线在室温附近具有马氏体和磁化转变，并且在外加5 T磁场下具有相当大的磁化值。在 285 和 295 K 温度之间观察到明显的可逆变磁行为。等温 M-H 曲线也证实了变磁转变并通过麦克斯韦关系提供了磁热效应。该系统经历了奥氏体-马氏体相变，并且发现在整个马氏体转变过程中磁熵的变化非常大，因此这导致了逆磁热效应。