TY - JOUR
T1 - Electron Correlation Enhances Orbital Polarization at a Ferromagnetic Metal/Insulator Interface
T2 - Depth-Resolved X-ray Magnetic Circular Dichroism and First-Principles Study
AU - Sakamoto, Shoya
AU - Tsujikawa, Masahito
AU - Shirai, Masafumi
AU - Amemiya, Kenta
AU - Miwa, Shinji
N1 - Funding Information:
This work was performed under the approval of the Photon Factory Program Advisory Committee (Proposal No. 2019S2-003). This work was supported by JSPS KAKENHI (Nos. JP18H03880 and JP20K15158), and the Spintronics Research Network of Japan (Spin-RNJ). We thank T. Higo and S. Nakatsuji of the University of Tokyo for MOKE measurements. We also thank S. Fukami of Tohoku University, X. Xu, T. Ohkubo, and K. Hono of NIMS for discussions.
Publisher Copyright:
© 2022 ACS Applied Electronic Materials. All right reserved.
PY - 2022/4/26
Y1 - 2022/4/26
N2 - The Fe(CoB)/MgO interface is vital to spintronics as it exhibits the tunneling magnetoresistance (TMR) effect and interfacial perpendicular magnetic anisotropy (PMA) simultaneously. To further enhance TMR and PMA for the development of high-density magnetoresistive random access memory, it is essential to clarify the behavior of Fe atoms interfaced with MgO. This study reveals that the spin and orbital magnetic moments of Fe are enhanced at the Fe/MgO interface. The enhancement in the orbital magnetic moment is much more significant than that predicted by the standard density functional theory. Theoretical calculations based on the orbital polarization correction reproduce this enhancement, the origin of which is attributed to the electron-electron correlation resulting from electron localization at the Fe/MgO interface. The present findings highlight the importance of electron-electron correlation at ferromagnet/oxide interfaces, which has often been disregarded in spintronics.
AB - The Fe(CoB)/MgO interface is vital to spintronics as it exhibits the tunneling magnetoresistance (TMR) effect and interfacial perpendicular magnetic anisotropy (PMA) simultaneously. To further enhance TMR and PMA for the development of high-density magnetoresistive random access memory, it is essential to clarify the behavior of Fe atoms interfaced with MgO. This study reveals that the spin and orbital magnetic moments of Fe are enhanced at the Fe/MgO interface. The enhancement in the orbital magnetic moment is much more significant than that predicted by the standard density functional theory. Theoretical calculations based on the orbital polarization correction reproduce this enhancement, the origin of which is attributed to the electron-electron correlation resulting from electron localization at the Fe/MgO interface. The present findings highlight the importance of electron-electron correlation at ferromagnet/oxide interfaces, which has often been disregarded in spintronics.
KW - Fe/MgO
KW - X-ray magnetic circular dichroism
KW - magnetic tunnel junction
KW - perpendicular magnetic anisotropy
KW - spintronics
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U2 - 10.1021/acsaelm.2c00049
DO - 10.1021/acsaelm.2c00049
M3 - Article
AN - SCOPUS:85127709083
SN - 2637-6113
VL - 4
SP - 1794
EP - 1799
JO - ACS Applied Electronic Materials
JF - ACS Applied Electronic Materials
IS - 4
ER -