Wang Xiaotian, Cheng Zhenxiang, Wang Wenhong
School of Physical Science and Technology, Southwest University, Chongqing 400715, China.
Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong 2500, Australia.
Materials (Basel). 2017 Oct 20;10(10):1200. doi: 10.3390/ma10101200.
For theoretical designing of full-Heusler based spintroinc materials, people have long believed in the so-called Site Preference Rule (SPR). Very recently, according to the SPR, there are several studies on XA-type Hafnium-based Heusler alloys X₂YZ, i.e., Hf₂VAl, Hf₂CoZ (Z = Ga, In) and Hf₂CrZ (Z = Al, Ga, In). In this work, a series of Hf₂-based Heusler alloys, Hf₂VZ (Z = Al, Ga, In, Tl, Si, Ge, Sn, Pb), were selected as targets to study the site preferences of their atoms by first-principle calculations. It has been found that all of them are likely to exhibit the L2₁-type structure instead of the XA one. Furthermore, we reveal that the high values of spin-polarization of XA-type Hf₂VZ (Z = Al, Ga, In, Tl, Si, Ge, Sn, Pb) alloys have dropped dramatically when they form the L2₁-type structure. Also, we prove that the electronic, magnetic, and physics nature of these alloys are quite different, depending on the L2₁-type or XA-type structures.
对于基于全赫斯勒合金的自旋电子材料的理论设计，人们长期以来一直相信所谓的位偏好规则（SPR）。就在最近，根据位偏好规则，有几项关于XA型铪基赫斯勒合金X₂YZ的研究，即Hf₂VAl、Hf₂CoZ（Z = Ga、In）和Hf₂CrZ（Z = Al、Ga、In）。在这项工作中，一系列基于Hf₂的赫斯勒合金Hf₂VZ（Z = Al、Ga、In、Tl、Si、Ge、Sn、Pb）被选为研究对象，通过第一性原理计算来研究其原子的位偏好。研究发现，它们都可能呈现L2₁型结构而非XA型结构。此外，我们揭示出，XA型Hf₂VZ（Z = Al、Ga、In、Tl、Si、Ge、Sn、Pb）合金在形成L2₁型结构时，其高自旋极化值大幅下降。而且，我们证明了这些合金的电子、磁性和物理性质因L2₁型或XA型结构而有很大差异。
