Cr、Fe和Co掺杂对NiMnGa马氏体相变和磁性能的影响

用电弧熔炼和甩带快淬的方法制备了NiMnGa基磁性形状记忆合金。研究了Cr、Fe和Co元素掺杂对磁性形状记忆合金NiMnGa的马氏体相变和磁性的影响。结果表明,在Ni50Mn33Ga17中用少量Cr替代Ni,马氏体相变温度随着Cr的增加而下降,而居里温度则升高,在NiCrMnGa中进一步掺杂Fe或Co都可以进一步降低马氏体相变温度并提高居里温度,马氏体相变温度的变化基本上遵循随电子浓度降低而降低的规律;此外,在NiMnGa中用Cr取代Ni会使得马氏体相和母相的铁磁交换作用同时增强,进一步在NiCrMnGa中掺杂Co对提高母相磁化强度更为有利,而掺杂Fe则对抑制马氏体相磁化强度增加更为有利。

Effects of Cr,Fe and Co doping on the martensitic transformation and magnetic property of NiMnGa alloys

The effect of Cr, Fe and Co doping on the martensitic transformation and magnetic property of NiMnGa magnetic shape memory alloy has been investigated. The results indicate that the temperature of martensitic transformation decreases and the Curie temperature increases with the substitution of Cr for Ni in Ni50Mn33Ga17. With doping of Fe or Co in NiCrMnGa, the Curie temperature increases and the temperature of martensitic transformation further decreases, following the rule that the temperature of martensitic transformation decreases with the decreasing of the electron concentration. In addition, the substitution of Cr for Ni in NiMnGa can enhance the ferromagnetic exchange in both the martensite and austenite. In NiCrMnGa, the doping of Co is beneficial for strengthening the magnetization of austenite while the doping of Fe is beneficial for suppressing the enhancement of the magnetization of the martensite.