Effect of atomic disorder on electronic, magnetic and electron-transport properties of Ti2MnAl
Effect of atomic disorder on electronic, magnetic and electron-transport properties of Ti2MnAl
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DOI：
10.1016/j.jallcom.2021.162625
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发表时间：
2021-11
影响因子：
6.2
通讯作者：
P. Lukashev;Zachary Lehmann;L. Stuelke;R. Filippone;Bishnu R. Dahal;S. Valloppilly;J. Waybright;A. Pathak;Y. Huh;P. Shand;P. Kharel
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文献类型：
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作者：
P. Lukashev;Zachary Lehmann;L. Stuelke;R. Filippone;Bishnu R. Dahal;S. Valloppilly;J. Waybright;A. Pathak;Y. Huh;P. Shand;P. Kharel
本文采用计算和实验相结合的方法研究了原子无序对Ti2MnAl Heusler合金电子、磁性和电子输运性质的影响。Ti_2MnAl在倒置立方晶体结构中表现出无自旋带隙的半导体行为，而规则立方结构基本上是非自旋极化的和非磁性的。在这里，我们分析了三种类型的原子无序，即A2，B2和D03，这是常见的Heusler合金。我们的第一性原理计算表明，所有三种类型的障碍有一个相对较小的影响，在规则的立方晶体（原型Cu2MnAl）结构的非自旋极化性质的Ti2MnAl。同时，倒置立方相（原型Hg2TiCu）在A2和B2无序结构中保留了显著程度的自旋极化。特别是，A2和B2类型的反立方相的无序分别导致约50%和74%的自旋极化。D03无序反相具有小于10%的显著更小的自旋极化。所有考虑的结构铁磁排列，除了B2无序和非无序的规则立方相，这是非磁性的。我们的实验结果与部分A2和B2无序型Ti2MnAl的预测性能是一致的。虽然原子无序在所考虑的系统中应该最小化或避免实际实现，但其类型可能对基于自旋的电子学中的潜在应用起决定性作用。
We report the combined computational and experimental study on the effect of atomic disorder on electronic, magnetic, and electron-transport properties of Ti2MnAl Heusler alloy. Ti2MnAl is predicted to exhibit spin-gapless semiconducting behavior in the inverted cubic crystal structure, while the regular cubic structure is essentially non-spin-polarized and non-magnetic. Here, we analyze three types of atomic disorder, namely, A2, B2, and D03, which are commonly observed in Heusler alloys. Our first-principles calculations indicate that all three types of disorder have a relatively small effect on a non-spin-polarized nature of Ti2MnAl in the regular cubic crystal (prototype Cu2MnAl) structure. At the same time, the inverted cubic phase (prototype Hg2TiCu) retains a significant degree of spin-polarization in A2 and B2 disordered structures. In particular, A2 and B2 types of disorder of the inverted cubic phase result in a spin-polarization of about 50% and 74%, respectively. The D03disordered inverted phase has a significantly smaller spin-polarization of less than 10%. All considered structures align ferrimagnetically, except the B2-disordered and non-disordered regular cubic phases, which are non-magnetic. Our experimental results are consistent with the predicted properties of Ti2MnAl with partial A2 and B2 disorder types. While atomic disorder in a considered system should be minimized or avoided for practical implementations, its type may play a decisive role for potential applications in spin-based electronics.