Role of top and bottom interfaces of a Pt/Co/AlOx system in Dzyaloshinskii-Moriya interaction, interface perpendicular magnetic anisotropy, and magneto-optical Kerr effect
Nam-Hui Kim,
Jaehun Cho,
Jinyong Jung,
Dong-Soo Han,
Yuxiang Yin,
June-Seo Kim,
Henk J. M. Swagten,
Kyujoon Lee,
Myung-Hwa Jung,
Chun-Yeol You
Affiliations
Nam-Hui Kim
Department of Emerging Materials Science, DGIST, Daegu 42988, South Korea
Jaehun Cho
Department of Physics, Inha University, Incheon 22212, South Korea
Jinyong Jung
Department of Emerging Materials Science, DGIST, Daegu 42988, South Korea
Dong-Soo Han
Department of Applied Physics, Center for NanoMaterials, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
Yuxiang Yin
Department of Applied Physics, Center for NanoMaterials, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
June-Seo Kim
Department of Applied Physics, Center for NanoMaterials, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
Henk J. M. Swagten
Department of Applied Physics, Center for NanoMaterials, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
Kyujoon Lee
Institute of Physics, Johannes Gutenberg-Universität Mainz, Mainz 55099, Germany
Myung-Hwa Jung
Department of Physics, Sogang University, Seoul 04107, South Korea
Chun-Yeol You
Department of Emerging Materials Science, DGIST, Daegu 42988, South Korea
We investigate the role of top and bottom interfaces in inversion symmetry-breaking Pt/Co/AlOx systems by inserting ultra-thin Cu layers. Wedge-type ultrathin Cu layers (0-0.5 nm) are introduced between Pt/Co or Co/AlOx interfaces. Interface sensitive physical quantities such as the interfacial Dzyaloshinskii-Moriya interaction (iDMI) energy density, the interfacial perpendicular magnetic anisotropy (iPMA), and the magneto-optical Kerr effects (MOKE) are systematically measured as a function of Cu-insertion layer thickness. We find that the Cu-insertion layer in the bottom interface (Pt/Co) plays a more important role in iDMI, PMA, and MOKE. In contrast, the top interface (Co/AlOx) noticeably contributes to only PMA, while its contributions to iDMI and MOKE enhancement are less significant. Although the PMA mainly comes from the bottom interface (Pt/Co), the Cu-insertion layers of all interfaces (Pt/Co, Co/AlOx) influence PMA. For iDMI, only the Cu-insertion layer in the bottom interface exerts SOC suppression which leads iDMI energy to decrease rapidly.
