Department of Physics, Bielefeld University, 33501 Bielefeld, Germany.
J Phys Condens Matter. 2011 Jan 26;23(3):036001. doi: 10.1088/0953-8984/23/3/036001. Epub 2010 Dec 21.
The Heusler compounds Mn(2)TiZ (Z = Al, Ga, In, Si, Ge, Sn, P, As, Sb) are of great interest due to their potential ferrimagnetic properties and high spin polarization. Here, we present calculations of the structural and magnetic properties of these materials. Their magnetic moment follows the Slater-Pauling rule m = N(V) - 24. None of them is actually a perfect half-metallic ferrimagnet, but some exhibit more than 90% spin polarization and Curie temperatures well above room temperature. The exchange interactions are complex; direct and indirect exchange contributions are identified. The Curie temperature scales with the total magnetic moment, and it has a positive pressure dependence. The role of the Z element is investigated: it influences the properties of the compounds mainly via its valence electron number and its atomic radius, which determines the lattice parameter. Based on these results, Mn(2)TiSi, Mn(2)TiGe, and Mn(2)TiSn are proposed as candidates for spintronic applications.
由于 Heusler 化合物 Mn2TiZ（Z=Al、Ga、In、Si、Ge、Sn、P、As、Sb）具有潜在的铁磁性和高自旋极化率，因此受到了广泛关注。在这里，我们对这些材料的结构和磁性进行了计算。它们的磁矩遵循斯莱特-保尔ing 规则 m = N(V) - 24。实际上，它们都不是完美的半金属铁磁体，但有些表现出超过 90%的自旋极化率和居里温度远高于室温。交换相互作用很复杂；已经确定了直接和间接交换贡献。居里温度与总磁矩成正比，并且具有正的压力依赖性。研究了 Z 元素的作用：它主要通过其价电子数及其原子半径来影响化合物的性质，原子半径决定了晶格参数。基于这些结果，Mn2TiSi、Mn2TiGe 和 Mn2TiSn 被提议用于自旋电子学应用。
