运用基于密度泛函理论的第一性原理,对3种 Heusler合金Mn2RhZ(Z=In, Sn, Sb)的原子占位、晶体结构、晶格畸变和磁学性质等性能进行了研究.结果表明, Hg2CuTi型结构3种Heusler合金相比Cu2MnAl型结构表现得更为稳定;在由立方结构至四方结构的变形中,Mn2RhZ(Z=In, Sn, Sb)分别在c/a=1.38,1.29,1.29处出现总能量的最小值,分别对应稳定的马氏体相;Mn2RhZ(Z=In, Sn, Sb)的总磁矩主要源于Mn原子磁矩,奥氏体相下Mn2RhSb合金中的2个Mn原子磁矩呈现反平行耦合,表现出铁磁性,而在奥氏体、马氏体相下Mn2RhZ(Z=In, Sn)以及马氏体相下Mn2RhSb合金表现出亚铁磁结构,因而Mn2RhZ(Z=In, Sn, Sb)是潜在的具有磁性形状记忆效应的合金材料.
The electronic structure and magnetic structure optimization on cubic austenitic Mn2RhZ(Z=In, Sn, Sb)alloy in Cu2MnAl and the Hg2CuTi type structures have been investigated by using first principle calculations. In the austenitic phase, the Mn2RhZ(Z=In, Sn, Sb)alloy of Hg2CuTi type structure is more stable. With the tetragonal distortion, the global energy minimum occurs at c/a=1.38, 1.29, 1.29. The total magnetic moments of Mn2RhZ(Z=In,Sn,Sb)mainly determined by the anti-parallel aligned Mn(A)and Mn(B)atoms spin moments. The magnetic moments of two Mn atoms in the Mn2RhSb alloy in the austenite phase exhibit anti-parallel coupling, while the Mn2RhZ(Z=In, Sn)in austenite and martensite phases and the Mn2RhSb alloy in martensite phase are ferrimagnetic. The Mn2RhZ(Z=In, Sn, Sb)alloys are potential materials with significant magnetic shape memory effect.
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