中国物理B ›› 2014, Vol. 23 ›› Issue (6): 67102-067102.doi: 10.1088/1674-1056/23/6/067102

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Electronic and magnetic properties of BiFeO3 with intrinsic defects：First-principles prediction

杨瑞鹏a, 林思贤a, 方潇功a, 秦明辉a, 高兴森a, 曾敏a, 刘俊明b   

  1. a Institute for Advanced Materials, South China Normal University, Guangzhou 510006, China;
    b Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China
  • 收稿日期:2013-10-31 修回日期:2013-12-03 出版日期:2014-06-15 发布日期:2014-06-15
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 51101063, 51072061, and 51172067) and the Natural Science Foundation of Guangdong Province, China (Grant No. S2011040003205).

Electronic and magnetic properties of BiFeO3 with intrinsic defects：First-principles prediction

Yang Rui-Peng (杨瑞鹏)a, Lin Si-Xian (林思贤)a, Fang Xiao-Gong (方潇功)a, Qin Ming-Hui (秦明辉)a, Gao Xing-Sen (高兴森)a, Zeng Min (曾敏)a, Liu Jun-Ming (刘俊明)b   

  1. a Institute for Advanced Materials, South China Normal University, Guangzhou 510006, China;
    b Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China
  • Received:2013-10-31 Revised:2013-12-03 Online:2014-06-15 Published:2014-06-15
  • Contact: Zeng Min E-mail:zengmin@scnu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 51101063, 51072061, and 51172067) and the Natural Science Foundation of Guangdong Province, China (Grant No. S2011040003205).

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摘要： The electronic structure, magnetism, and dielectric functions of BiFeO3 with intrinsic vacancies, including Bi-, Fe-, and O-vacancies (denoted as VFe, VBi, and VO, respectively) are investigated using the first-principles density functional theory plus U calculations. It is revealed that the structural distortions associated with those vacancies impose significant influences on the total density of state and magnetic behaviors. The existence of VBi favors the excitation of the O2p state into the band gap at 0.4 eV, while the O2p and Fe3d orbitals are co-excited into the band gap around 0.45 eV in VFe. Consequently, a giant net magnetic moment of 1.96 uB is generated in VFe, and a relatively small moment of 0.13 uB is induced in VBi, whereas VO seems magnetically inactive. The giant magnetic moment generated in VFe originates from the suppression of the spatially modulated antiferromagnetic spin structure. Furthermore, VFe and VBi have strong influences on dielectric function, and induce some strong peaks to occur in the lower energy level. In contrast, VO has a small effect.

关键词: BiFeO3, vacancies, magnetization, dielectric functions

Abstract: The electronic structure, magnetism, and dielectric functions of BiFeO3 with intrinsic vacancies, including Bi-, Fe-, and O-vacancies (denoted as VFe, VBi, and VO, respectively) are investigated using the first-principles density functional theory plus U calculations. It is revealed that the structural distortions associated with those vacancies impose significant influences on the total density of state and magnetic behaviors. The existence of VBi favors the excitation of the O2p state into the band gap at 0.4 eV, while the O2p and Fe3d orbitals are co-excited into the band gap around 0.45 eV in VFe. Consequently, a giant net magnetic moment of 1.96 uB is generated in VFe, and a relatively small moment of 0.13 uB is induced in VBi, whereas VO seems magnetically inactive. The giant magnetic moment generated in VFe originates from the suppression of the spatially modulated antiferromagnetic spin structure. Furthermore, VFe and VBi have strong influences on dielectric function, and induce some strong peaks to occur in the lower energy level. In contrast, VO has a small effect.

Key words: BiFeO3, vacancies, magnetization, dielectric functions

中图分类号:  (Electron density of states and band structure of crystalline solids)

  • 71.20.-b
71.55.-i (Impurity and defect levels) 77.22.-d (Dielectric properties of solids and liquids) 75.10.-b (General theory and models of magnetic ordering)