title: Origin of interfacial perpendicular magnetic anisotropy in MgO/CoFe/metallic capping layer structures.
abstract: Spin-transfer-torque magnetic random access memory (STT-MRAM) attracts extensive attentions due to its non-volatility, high density and low power consumption. The core device in STT-MRAM is CoFeB/MgO-based magnetic tunnel junction (MTJ), which possesses a high tunnel magnetoresistance ratio as well as a large value of perpendicular magnetic anisotropy (PMA). It has been experimentally proven that a capping layer coating on CoFeB layer is essential to obtain a strong PMA. However, the physical mechanism of such effect remains unclear. In this paper, we investigate the origin of the PMA in MgO/CoFe/metallic capping layer structures by using a first-principles computation scheme. The trend of PMA variation with different capping materials agrees well with experimental results. We find that interfacial PMA in the three-layer structures comes from both the MgO/CoFe and CoFe/capping layer interfaces, which can be analyzed separately. Furthermore, the PMAs in the CoFe/capping layer interfaces are analyzed through resolving the magnetic anisotropy energy by layer and orbital. The variation of PMA with different capping materials is attributed to the different hybridizations of both d and p orbitals via spin-orbit coupling. This work can significantly benefit the research and development of nanoscale STT-MRAM.
authors.affiliation: Fert Beijing Institute, Beihang University, Beijing 100191, China.|School of Electronic and Information Engineering, Beihang University, Beijing 100191, China.
authors.forename: Shouzhong
authors.initials: S
authors.lastname: Peng
authors.affiliation: Fert Beijing Institute, Beihang University, Beijing 100191, China.|School of Electronic and Information Engineering, Beihang University, Beijing 100191, China.
authors.forename: Mengxing
authors.initials: M
authors.lastname: Wang
authors.affiliation: Univ. Grenoble Alpes, INAC-SPINTEC, F-38000 Grenoble, France; CEA, INAC-SPINTEC, F-38000 Grenoble, France and CNRS, SPINTEC, F-38000 Grenoble, France.
authors.forename: Hongxin
authors.initials: H
authors.lastname: Yang
authors.affiliation: Fert Beijing Institute, Beihang University, Beijing 100191, China.|School of Electronic and Information Engineering, Beihang University, Beijing 100191, China.
authors.forename: Lang
authors.initials: L
authors.lastname: Zeng
authors.affiliation: Fert Beijing Institute, Beihang University, Beijing 100191, China.|School of Electronic and Information Engineering, Beihang University, Beijing 100191, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Nan
authors.affiliation: Fert Beijing Institute, Beihang University, Beijing 100191, China.|School of Electronic and Information Engineering, Beihang University, Beijing 100191, China.
authors.forename: Jiaqi
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Fert Beijing Institute, Beihang University, Beijing 100191, China.|School of Electronic and Information Engineering, Beihang University, Beijing 100191, China.
authors.forename: Youguang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Univ. Grenoble Alpes, INAC-SPINTEC, F-38000 Grenoble, France; CEA, INAC-SPINTEC, F-38000 Grenoble, France and CNRS, SPINTEC, F-38000 Grenoble, France.
authors.forename: Ali
authors.initials: A
authors.lastname: Hallal
authors.affiliation: Univ. Grenoble Alpes, INAC-SPINTEC, F-38000 Grenoble, France; CEA, INAC-SPINTEC, F-38000 Grenoble, France and CNRS, SPINTEC, F-38000 Grenoble, France.
authors.forename: Mairbek
authors.initials: M
authors.lastname: Chshiev
authors.affiliation: Department of Electrical Engineering, University of California, Los Angeles, California 90095, USA.
authors.forename: Kang L
authors.initials: KL
authors.lastname: Wang
authors.affiliation: School of Materials Science and Engineering, Beihang University, Beijing 100191, China.
authors.forename: Qianfan
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Fert Beijing Institute, Beihang University, Beijing 100191, China.|School of Electronic and Information Engineering, Beihang University, Beijing 100191, China.
authors.forename: Weisheng
authors.initials: W
authors.lastname: Zhao