Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Straße 40, D-01187 Dresden, Germany.
J Phys Condens Matter. 2013 May 22;25(20):206006. doi: 10.1088/0953-8984/25/20/206006. Epub 2013 Apr 30.
We investigate the structural stability and magnetic properties of the cubic, tetragonal and hexagonal phases of Mn3Z (Z=Ga, Sn and Ge) Heusler compounds using first-principles density-functional theory. We propose that the cubic phase plays an important role as an intermediate state in the phase transition from the hexagonal to the tetragonal phases. Consequently, Mn3Ga and Mn3Ge behave differently from Mn3Sn, because the relative energies of the cubic and hexagonal phases are different. This result agrees with experimental observations for these three compounds. The weak ferromagnetism of the hexagonal phase and the perpendicular magnetocrystalline anisotropy of the tetragonal phase obtained in our calculations are also consistent with experiment.
我们使用第一性原理密度泛函理论研究了 Mn3Z（Z=Ga、Sn 和 Ge）Heusler 化合物的立方、四方和六方相的结构稳定性和磁性。我们提出立方相在六方相向四方相的相变过程中起着重要的中间相作用。因此，Mn3Ga 和 Mn3Ge 的行为与 Mn3Sn 不同，因为立方相和六方相的相对能量不同。这一结果与这三种化合物的实验观察结果一致。我们的计算还得到了六方相的弱铁磁性和四方相的垂直磁晶各向异性，这与实验结果一致。
