Abstract The anomalous staircase-like magnetization behavior has been investigated in a Fe–Mn-Ga magnetic shape memory alloy. Here, we elucidate the underlying mechanism for such anomalous magnetic behavior is caused by the magnetic-field-induced structural transformation occurring at low temperature. The reversal of structural phase transformation in a sufficient thermodynamics area is accounted for the abrupt changes of the magnetization behavior. Moreover, a giant magnetocaloric effect with isothermal entropy change of ~60 J kg−1K−1 under 5 T magnetic field was discovered, which is due to the antiferromagnetic to ferromagnetic transition, different from the previous report in magnetic shape memory alloys. The present work provides insights into the interplay between magnetism and structure in magnetic shape memory alloys, and instructive understanding of the anomalous staircase-like magnetization behavior in other materials undergoing a magnetostructural transition.

中文翻译：

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Fe-Mn-Ga磁性形状记忆合金的异常阶梯状磁化行为和巨磁热效应

摘要 研究了 Fe-Mn-Ga 磁性形状记忆合金的异常阶梯状磁化行为。在这里，我们阐明了这种异常磁性行为的潜在机制是由低温下发生的磁场诱导结构转变引起的。在足够的热力学区域中结构相变的逆转是磁化行为的突然变化的原因。此外，还发现了在 5 T 磁场下等温熵变化约 60 J kg-1K-1 的巨磁热效应，这是由于反铁磁到铁磁的转变，与之前在磁性形状记忆合金中的报道不同。目前的工作提供了对磁性形状记忆合金中磁性和结构之间相互作用的见解，