Co影响Ni-Mn-Ga合金马氏体相变的第一性原理分析

First-Principle Study on the Effect of Co Addition on the Martensitic Transformation of Ni-Mn-Ga Ferromagnetic Shape Memory Alloys

摘要:

采用基于密度泛函理论的第一原理平面波赝势法，研究了掺杂Co元素对Ni-Mn-Ga磁性形状记忆合金的能态密度分布的影响规律，阐明了Co对马氏体相变作用机理。研究表明，随Co含量增加，更多的Co3d-Mn3d杂化取代了Ni3d-Mn3d杂化，使母相稳定性提高，马氏体相变温度降低。Co的加入对Ni-Mn-Ga-Co母相的自旋向上能态密度几乎没有影响，但明显改变自旋向下能态密度。

Abstract:

The effect of Co addition on the density of states (DOS) distribution of Ni-Mn-Ga ferromagnetic shape memory alloys was investigated by first-principles plane-wave pseudo-potential method based on the density functional theory. The mechanism of effect of Co element on martensitic transformation of Ni-Mn-Ga alloy was clarified. Results show that with Co content increasing, more Co3d-Mn3d hybridization replaced Ni3d-Mn3d, improving parent phase stability and decreasing martensitic transformation temperature. In addition, it is noted that Co addition has little effect on majority-spin DOS of Ni-Mn-Ga-Co parent phase, but changes minority-spin DOS significantly.