| Author Name | Affiliation | | Weifu Cen | Guidance Center of Undergraduate Innovation and Entrepreneurship, Guizhou Minzu University, Guiyang 550025, China
Special and Key Laboratory of Guizhou Provincial Higher Education for Photoelectronic Information Processing and Analysis, Guizhou Minzu University, Guiyang 550025, China | | Lin Lyu | Special and Key Laboratory of Guizhou Provincial Higher Education for Photoelectronic Information Processing and Analysis, Guizhou Minzu University, Guiyang 550025, China | | Yinye Yang | Guidance Center of Undergraduate Innovation and Entrepreneurship, Guizhou Minzu University, Guiyang 550025, China
Special and Key Laboratory of Guizhou Provincial Higher Education for Photoelectronic Information Processing and Analysis, Guizhou Minzu University, Guiyang 550025, China | | Menghui Fan | Special and Key Laboratory of Guizhou Provincial Higher Education for Photoelectronic Information Processing and Analysis, Guizhou Minzu University, Guiyang 550025, China |
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| Abstract: |
| A system study of the three-dimensional normal stress for regulating electronic structure and magnetic property of Fe2Ge is studied. The density states of Fe more than 92% contribution come from Fe 3d, the density states of Ge mainly contributed from Ge 4p and Ge 4s, and the Fe 3d spin induces the Ge 4p electron transfer. The inductive effect increases germanium electron energy, weakens the Fe spin density of states, opposes the stability of the ferromagnetic state. The magnetic moment varies from 5 to 3 μB with the stress charges from -30 to 30 GPa. The charge of Fe is negative whereas the Ge atom is positively charged, the Fe atom loses charge, the charge transfers to the Ge atom. The unevenly distributed charge forms the new occupy state and spin polarization state in the Fe2Ge electron structure system. The Fe is the electron donor, the total electron is transferred to Ge, but the total numbers of gain electron and total numbers of lost electron are not equal, so the Fe2Ge electron system may have hybridization between the Fe 3d state and Ge 4p state. The magnetic of Fe2Ge mainly comes from the unoccupied Fe 3d orbital, the Fe 3d is positive spin-polarization state and the spin-polarization strength is decreased, the Ge 4p is negative spin-polarization state and the spin-polarization strength are increased. Moreover, electrons-spin polarization is relevant to the structure parameters of the Fe2Ge system, and controls spin-polarized electronic behavior by means of adjusting ferromagnetic. |
| Key words: Fe2Ge electronic structure magnetic property stress controlling first-principles |
| DOI：10.11916/j.issn.1005-9113.17125 |
| Clc Number:O44 |
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| Descriptions in Chinese: |
| 三向正应力调控Fe2Ge的电子结构和电磁特性 岑伟富1，2, 吕 林2, 杨吟野1，2，范梦慧2 （1. 贵州民族大学 大学生创新创业指导中心，贵阳 550025；2. 贵州民族大学 贵州省教育厅光电信息分析与处理特色重点实验室，贵阳 550025） 创新点说明：Fe2Ge的磁性主要来自于Fe的3d态电子，其电子迁移和跃迁受外应力的影响非常显著，因此采用三向应力调控Fe2Ge调控3d态电子，达到调控Fe2Ge电子结构和电磁特性的目的。 研究目的： 通过三向应力调控Fe2Ge电子结构和电磁特性，总结出应力调控其电磁特性的规律，为实验调控Fe2Ge电子结构和电磁特性提供指导。 研究方法： 采用基于密度泛函理论的第一性原理方法计算Fe2Ge电子结构和电磁特性。选取广义梯度近似(GGA)下的PBE函数计算交换关联能，通过Hubbard参数U（排斥能）和J（交换能）来描述这种强关联作用，利用GGA+U方法进行计算对Fe2Ge磁性能进行计算，并通过三向应力对Fe2Ge磁性能进行调控，分析其调控机理。 结果： 1. Fe的态密度92%来自于3d，Fe 3d自旋诱导Ge 4p电子转移。 2. Fe原子失去电荷，是电荷供体，电荷转移到Ge原子上，但Ge获得电子的总数目和Fe失去电子的总数不相等。 3. Fe2Ge随着应力从-30Gpa到30Gpa的变化过程中，磁矩的变化范围在3uB~5uB之间变化。 结论： 1. Fe 3d态电子诱导Ge 4p态电子转移，增加Ge电子能量，削弱Fe的自旋态密度。 2. 在Fe2Ge电子结构体系中，不均匀分布的电荷形成了新的占据态和自旋极化状态。 3. Fe 3d状态与Ge 4p状态之间的Fe2Ge电子系统可能存在杂化。Fe2Ge的磁性主要来自于未被占领的Fe三维轨道，Fe三维为正自旋极化状态，自旋极化强度减小，Ge 4p为负自旋极化状态，自旋极化强度增加。 关键词：Fe2Ge； 电子结构；磁学特性；应力调控；第一性原理 |
