Modeling the structural distortion and magnetic ground state of the polar lacunar spinel GaV4Se8
Modeling the structural distortion and magnetic ground state of the polar lacunar spinel GaV4Se8
复制标题
模拟极腔尖晶石 GaV4Se8 的结构畸变和磁基态
DOI：
10.1103/physrevb.100.045131
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发表时间：
2019
影响因子：
3.7
通讯作者：
Seshadri, Ram
中科院分区：
文献类型：
--
作者：
Schueller, Emily C.;Zuo, Julia L.;Bocarsly, Joshua D.;Kitchaev, Daniil A.;Wilson, Stephen D.;Seshadri, Ram
多孔尖晶石是一种由V原子组成的四面体团簇控制其性质的材料。已知该化合物在空间群中经历极性畸变到基态结构，并且具有相对小的磁矩的铁磁有序。我们发展到这种材料中的晶体结构和磁序之间的关系的理解，并在建立观察到的基态使用第一性原理密度泛函理论（DFT）电子结构计算的电子相关性的影响。由于电子在团簇内是离域的，但在团簇之间是局域的，因此模拟电子相关性的常用方法（例如使用Hubbardin方案）无法充分地重新创建实验基态。相反，我们发现的实验基态的相关能的随机相位近似很好地表示。此外，我们发现磁性和晶体结构在这种材料中是强耦合的，只有在簇内的磁矩的某些安排可以稳定观察到的结构畸变。结合材料的各向异性、极性性质，磁结构耦合的强度表明应变的应用可以用于调节材料的磁特性。
The lacunar spinelis a material whose properties are dominated by tetrahedral clusters of V atoms. The compound is known to undergo a polar distortion to a ground state structure in thespace group, and orders ferromagnetically with a relatively small magnetic moment. We develop an understanding into the relationship between crystal structure and magnetic order in this material, and the influence of electron correlations in establishing the observed ground state using first-principles density functional theory (DFT) electronic structure calculations. Because electrons are delocalized withinclusters but localized between them, the usual approaches to simulate electron correlations—such as the use of the Hubbardinschemes—do not adequately recreate the experimental ground state. We find instead that the experimental ground state ofis well represented by the random-phase approximation to the correlation energy. Additionally, we find that magnetism and crystal structure are strongly coupled in this material, and only certain arrangements of magnetic moment within acluster can stabilize the observed structural distortion. In combination with the anisotropic, polar nature of the material, the strength of magnetostructural coupling indicates that application of strain could be used to tune the magnetic properties of.