Abstract The structural, magnetic, and magnetocaloric properties of the Ni54(FeMn)19Ga27 Heusler alloy have been presented, which has both Fe and Mn atoms at the 4a site of its austenite structure. The alloy is compared with the ternary alloys of the Ni54Fe19Ga27 and the Ni54Mn19Ga27. The alloy has a mixed-phase, which is L21 cubic and 14 M tetragonal at room temperature. The temperature-dependent magnetization curve exhibits ferromagnetic to paramagnetic phase transition in the range of 380–450 K. The obtained Curie temperature is 384 K. Fe and Mn are located at 4a site with the excess Ni and Ga in the non-stoichiometric alloy and therefore, ferromagnetic and antiferromagnetic interactions cause the decrease in the magnetization of the alloy and the Fe–Mn and Ni–Mn interactions led to high Curie temperature compared with that of both the Ni54Fe19Ga27 and Ni54Mn19Ga27. The saturation magnetization of the alloy is 53.97 Am2kg−1 under 2 T magnetic field at room temperature. The hysteresis curve is narrow and the coercivity is 0.19 mT under 2 T, and the alloy is a soft magnetic material. The Arrott plot curves indicate that the alloy shows the second-order phase transition and the magnetic entropy change is about 1.5 J kg−1K−1 under 2 T magnetic field.

中文翻译：

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Ni54(FeMn)19Ga27 Heusler 合金的结构、磁性和磁热性能

摘要 介绍了 Ni54(FeMn)19Ga27 Heusler 合金的结构、磁性和磁热性能，该合金在其奥氏体结构的 4a 位点具有 Fe 和 Mn 原子。该合金与Ni54Fe19Ga27和Ni54Mn19Ga27的三元合金进行比较。该合金具有混合相，在室温下为 L21 立方晶系和 14 M 四方晶系。随温度变化的磁化曲线在 380-450 K 范围内呈现铁磁性到顺磁性相变。获得的居里温度为 384 K。Fe 和 Mn 位于 4a 位点，非化学计量合金中过量的 Ni 和 Ga 和所以，铁磁和反铁磁相互作用导致合金磁化强度降低，与 Ni54Fe19Ga27 和 Ni54Mn19Ga27 相比，Fe-Mn 和 Ni-Mn 相互作用导致居里温度高。该合金在室温下2T磁场下的饱和磁化强度为53.97 Am2kg-1。磁滞曲线窄，2T以下矫顽力为0.19mT，合金为软磁材料。Arrott 曲线表明，该合金在 2 T 磁场下表现出二阶相变，磁熵变约为 1.5 J kg-1K-1。