Al掺杂对Fe_2Si电子结构和磁学特性的影响  

Effect of Al-doping on the electronic structure and magnetic properties of Fe_2Si

作　　者：李瑞杰 杨吟野 岑伟富[2,3] 吕林 谢泉 LI Rui-jie;YANG Yin-ye;CEN Wei-fu;LV Lin;XIE Quan(School of Materials Science and Engineering, Guizhou Minzu University, Guiyang 550025, China;College of Big Data and Information Engineering, Guizhou University, Guiyang 550025, China;Special and Key Laboratory of Guizhou Provincial Higher Education for Photoelectric Information Analysis and Processing, Guizhou Minzu University, Guiyang 550025, China)

机构地区：[1]贵州民族大学材料科学与工程学院,贵州贵阳550025 [2]贵州大学大数据与信息工程学院,贵州贵阳550025 [3]贵州民族大学贵州省光电信息分析与处理特色重点实验室,贵州贵阳550025

出　　处：《磁性材料及器件》2018年第2期5-9,共5页Journal of Magnetic Materials and Devices

基　　金：贵州省科技厅联合基金资助项目([2016]7077);贵州省教育厅青年科技人才成长项目([2016]166;贵州大学研究生创新基金项目(研理工[2017]011)

摘　　要：采用第一性原理的贋势平面波方法,计算了无掺杂和Al掺杂Fe_2Si体系的电子结构和磁学特性,并分析了Al掺杂对Fe_2Si体系电磁特性的影响。计算结果表明,未掺杂和Al掺杂Fe_2Si体系为半金属铁磁体,自旋向上的能带结构穿过费米面表现为金属特性,未掺杂Fe_2Si体系自旋向下的能带表现为间接带隙半导体特性,带隙值为0.464 eV;Al掺杂Fe_2Si体系自旋向下的能带表现为Z间的直接带隙半导体特性,带隙值为0.541 eV。Al掺杂使各原子磁矩和Fe_2Si体系的总磁矩均减小,体系的带隙值增加,相应的半金属隙也增加,并且使得体系自旋向下部分由间接带隙变为直接带隙半导体。Fe_2Si体系的半金属性和磁性主要来源于Fe-3d电子之间的d-d交换,Si-3p电子与Fe-3d电子之间的p-d杂化。综上所述,掺杂是调控半金属铁磁体Fe_2Si电磁特性的有效手段。The electronic structure and magnetic properties of undoped and Al-doped Fe2Si systems have been calculated by the first-principles pseudo-potential method.The results show that both the undoped and Al-doped Fe2Si systems are half-metallic ferromagnet with metal structure under spin-up.The spin-down band structure of undoped Fe2Si system exhibits an indirect semiconductor characteristic with a band-gap value of0.464eV;the Al-doped Fe2Si system exhibits a direct semiconductivity characteristic with a band-gap of0.541eV.Al doping decreases the magnetic moment of each atom and the total magnetic moment of Fe2Si system,increases both the band-gap value and increases the corresponding half-metal gap,and also it makes the spin-down parts of the system change from indirect to direct band-gap semiconductors.The half-metallic and magnetic properties of Fe2Si systems are mainly derived from the d-d exchange between Fe-3d electrons,p-d hybridization between Si-3p and Fe-3d electrons.Therefore,doping is an effective mean for regulating the electromagnetic properties of half-metallic ferromagnet Fe2Si.

关 键 词：Fe2Si体系 AL掺杂 电子结构 磁学特性 第一性原理 

分 类 号：O441.6[理学—电磁学]