Phase and d-d hybridization control via electron count for material property control in the X2FeAl material class
Phase and d-d hybridization control via electron count for material property control in the X2FeAl material class
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DOI：
10.1016/j.jmmm.2024.171932
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发表时间：
2024-03
影响因子：
2.7
通讯作者：
K. Law;Ridwan Nahar;Riley Nold;Michael Zengel;Justin Lewis;Adam J. Hauser
中科院分区：
文献类型：
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作者：
K. Law;Ridwan Nahar;Riley Nold;Michael Zengel;Justin Lewis;Adam J. Hauser
对正（L21）和逆（XA） Heusler化合物X2FeAl进行第一原理计算，其中X包括3d (Sc, Ti， V, Cr), 4d （Y, Zr, Nb, Mo）和5d （Hf, Ta， W）早期和中期柱过渡金属元素。随着总价电子数的增加，正反相之间的形成能差和d-d轨道杂化程度驱动了材料体系的磁性能（总磁矩和原子磁矩、自旋极化）和电子能（能带结构和投射态密度）。具体地说，随着价电子数的增加，x位原子磁矩在完全和逆Heusler相中呈现出越来越多的Fe特征。这可以用X位和fe位d轨道之间d-d杂化程度的变化来解释。X-和y -位（Fe）的PDOS在每一个正和逆Heusler级数上的同步能量转移为我们提供了通过成分控制自旋极化的见解。这项工作表明，需要在反位无序的框架和更广泛的成分背景下，全面研究Heusler合金的热力学相稳定性、磁矩和自旋极化。本研究的最终目标是通过提供一种基于实验或理论结果外推性质的方法，使实验结果的映射在寻找特定性质时受益。
First-principles calculations are performed for full (L21) and inverse (XA) Heusler compounds X2FeAl, where X comprise a range of 3d (Sc, Ti, V, Cr), 4d (Y, Zr, Nb, Mo), and 5d (Hf, Ta, W) early and middle column transition metal elements. The formation energy difference between full and inverse phase and the degree of d-d orbital hybridization with increasing total valence electron count are shown to drive the magnetic properties (total and atomic magnetic moments, spin polarization) and electronic properties (band structure and projected density of states) of the material system. Specifically, X-site atomic magnetic moments take on increasingly Fe character with increasing valence electron count, in both full and inverse Heusler phases. This can be explained by changes on the degree of d-d hybridization between X- and Fe-site d orbitals. Synchronized energy shifts in the PDOS of the X- and Y-sites (Fe) across each of the full and inverse Heusler series provide us insight to controlling spin polarization via composition. This work demonstrates the need to holistically study the thermodynamic phase stability, magnetic moments, and spin polarization of Heusler alloys, in the framework of anti-site disorder and in a wider compositional context. The end goal of this study is to benefit the mapping of experimental results in search of a specific property, by providing a methodology for extrapolating properties based on experimental or theoretical results.