title: MnGa-based fully perpendicular magnetic tunnel junctions with ultrathin Co2MnSi interlayers.
abstract: Because tetragonal structured MnGa alloy has intrinsic (not interface induced) giant perpendicular magnetic anisotropy (PMA), ultra-low damping constant and high spin polarization, it is predicted to be a kind of suitable magnetic electrode candidate in the perpendicular magnetic tunnel junction (p-MTJ) for high density spin transfer torque magnetic random access memory (STT-MRAM) applications. However, p-MTJs with both bottom and top MnGa electrodes have not been achieved yet, since high quality perpendicular magnetic MnGa films can hardly be obtained on the MgO barrier due to large lattice mismatch and surface energy difference between them. Here, a MnGa-based fully p-MTJ with the structure of MnGa/Co2MnSi/MgO/Co2MnSi/MnGa is investigated. As a result, the multilayer is with high crystalline quality, and both the top and bottom MnGa electrodes show well PMA. Meanwhile, a distinct tunneling magnetoresistance (TMR) ratio of 65% at 10 K is achieved. Ultrathin Co2MnSi films are used to optimize the interface quality between MnGa and MgO barrier. A strong antiferromagnetic coupling in MnGa/Co2MnSi bilayer is confirmed with the interfacial exchange coupling constant of -5erg/cm2. This work proposes a novel p-MTJ structure for the future STT-MRAM progress.
authors.affiliation: State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912,Beijing 100083, China.
authors.forename: Siwei
authors.initials: S
authors.lastname: Mao
authors.affiliation: State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912,Beijing 100083, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912,Beijing 100083, China.
authors.forename: Xupeng
authors.initials: X
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912,Beijing 100083, China.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912,Beijing 100083, China.
authors.forename: Dahai
authors.initials: D
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912,Beijing 100083, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912,Beijing 100083, China.
authors.forename: Jianbai
authors.initials: J
authors.lastname: Xia
authors.affiliation: State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912,Beijing 100083, China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Zhao