title: Enhancing the Spin-Orbit Coupling in Fe3O4Epitaxial Thin Films by Interface Engineering.
abstract: By analyzing the in-plane angular dependence of ferromagnetic resonance linewidth, we show that the Gilbert damping constant in ultrathin Fe3O4epitaxial films on GaAs substrate can be enhanced by thickness reduction and oxygen vacancies in the interface. At the same time, the uniaxial magnetic anisotropy due to the interface effect becomes significant. Using the element-specific technique of X-ray magnetic circular dichroism, we find that the orbital-to-spin moment ratio increases with decreasing film thickness, in full agreement with the increase in the Gilbert damping obtained for these ultrathin single-crystal films. Combined with the first-principle calculations, the results suggest that the bonding with Fe and Ga or As ions and the ionic distortion near the interface, as well as the FeO defects and oxygen vacancies, may increase the spin-orbit coupling in ultrathin Fe3O4epitaxial films and in turn provide an enhanced damping.
authors.affiliation: Department of Physics, Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University , Nanjing 211189, China.|Spintronics and Nanodevice Laboratory, Department of Electronics, University of York , York, U.K.|School of Electronic Science and Engineering, Southeast University , Nanjing 210096, China.
authors.forename: Zhaocong
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Spintronics and Nanodevice Laboratory, Department of Electronics, University of York , York, U.K.|Department of Electronic Engineering, Royal Holloway, University of London , Surrey, U.K.
authors.forename: Wenqing
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Physics, Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University , Nanjing 211189, China.
authors.forename: Jinjin
authors.initials: J
authors.lastname: Yue
authors.affiliation: Department of Physics, Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University , Nanjing 211189, China.
authors.forename: Qionghua
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Department of Physics, Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University , Nanjing 211189, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Spintronics and Nanodevice Laboratory, Department of Electronics, University of York , York, U.K.
authors.forename: Yongxiong
authors.initials: Y
authors.lastname: Lu
authors.affiliation: National Laboratory of Solid Microstructures and Center of Modern Analysis, Nanjing University , Nanjing, China.
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Sui
authors.affiliation: Department of Physics, Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University , Nanjing 211189, China.|National Laboratory of Solid Microstructures and Center of Modern Analysis, Nanjing University , Nanjing, China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Zhai
authors.affiliation: Department of Physics, Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University , Nanjing 211189, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Physics, Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University , Nanjing 211189, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Dong
authors.affiliation: Department of Physics, Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University , Nanjing 211189, China.
authors.forename: Jinlan
authors.initials: J
authors.lastname: Wang
authors.affiliation: Spintronics and Nanodevice Laboratory, Department of Electronics, University of York , York, U.K.
authors.forename: Yongbing
authors.initials: Y
authors.lastname: Xu
authors.affiliation: School of Electronic Science and Engineering, Southeast University , Nanjing 210096, China.
authors.forename: Baoping
authors.initials: B
authors.lastname: Wang
keywords: Gilbert damping; ferromagnetic resonance; half metallic Fe3O4; spin−orbit coupling; thin film