| 引用本文： |
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廖杨芳,谢泉,肖清泉,项飞羽,杨真.Mg2Si:Fe 电子结构及磁性的理论研究[J].低温物理学报,2018,(1):17-23. [点击复制]
- LIAO Yangfang,XIE Quan,XIAO Qingquan,XIANG Feiyu,YANG Zhen.Theoretical Studyonthe Electronic Structures and Magnetismof Mg２Si:Fe[J].LOW TEMPERATURE PHYSICAL LETTERS,2018,(1):17-23. [点击复制]
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| 摘要: |
| 采用基于密度泛函理论的第一性原理赝势平面波方法研究了Mg2Si:Fe体系的电子能带结构、 态密度和磁性．结果表明: 掺入的 Fe原子优先占据晶格中的空隙位, 也可能代替晶格中的 Mg位. 从能带结构和态密度可以看出, 当Fe原子位于晶格中空隙位时, 系统显示出金属性; 当 Fe占据 Mg位置时, 对于自旋向上电子态, 体系有一带隙存在, 系统呈现明显的半导体特性; 对于自旋向下电子态,Fe的替位掺杂在该体系内引入新的杂质能级, 杂质能级与导带价带分离, 且100% 自旋极化．两种位置的杂质, 上自旋电子和下自旋电子的态密度均明显不对称, 诱导出铁磁性, 且铁磁性主要由于 Fe的3d态电子诱导产生，Fe位于空隙位时,Fe原子的磁矩为1.69μB ;Fe占据 Mg位时, Fe原子的磁矩为1.38μB，说明原子磁矩与其所占位置和配位情况有关。 |
| 关键词: Mg2Si Fe 掺杂 电子结构 磁性 第一性原理计算 |
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| Theoretical Studyonthe Electronic Structures and Magnetismof Mg２Si:Fe |
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LIAO Yangfang1, XIE Quan2, XIAO Qingquan2, XIANG Feiyu3, YANG Zhen3
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| (1.College of Big Data and Information Engineering ,Guizhou University & College of Physics and Electronic Sciences ,Guizhou Normal University;2.College of Big Data and Information Engineering ,Guizhou University;3.College of Physics and Electronic Sciences ,Guizhou Normal University) |
| Abstract: |
| The electronic band structures, densities of states and magnetism of Mg２Si:Fe were investigated using a first principles plane-wave pseudopotential method based on the density functional theory． The results show that Fe atom is expected to be located at the interstitial site preferentially and perhaps at the Mg site in Mg２Si lattice. Calculations of the energy bands and densities of states show that system of Mg２Si:Fe presents the characteristic of metal when Fe atom is located at the interstitial site． However, Mg２Si:Fe offers the half-metal property when Fe atom substitutes for Mg． For both of the cases, the distributions of spin-projected total density of states are obviously asymmetric, so the ferromagnetism is induced． The ferromagnetism of Mg２Si: Fe is mainly due to the electrons of Fe 3d states． The calculated local magnetic moments are 1.69μB for Fe at interstitial site and 1.38μB for Fe at Mg site, respectively, which indicates that the magnetic moment of Fe atom strongly depends on the site occupied by the atom in the unit cell and on the configuration of the nearest neighbors． |
| Key words: Mg2Si, Fe-doped, bandstructures, magnetism,thefirst principlecalculations |
