Intrinsic Magnetic Proximity Effect at the Atomically Sharp Interface of Co x Fe3- xO4/Pt Grown by Molecular Beam Epitaxy

Shoto Nodo; Ichiro Yamane; Motohiro Suzuki; Jun Okabayashi; Seiya Yokokura; Toshihiro Shimada; Taro Nagahama

doi:10.1021/acsomega.3c00935

Intrinsic Magnetic Proximity Effect at the Atomically Sharp Interface of Co _x Fe_{3- x}O₄/Pt Grown by Molecular Beam Epitaxy

ACS Omega. 2023 Jul 4;8(28):24875-24882. doi: 10.1021/acsomega.3c00935. eCollection 2023 Jul 18.

Authors

Shoto Nodo¹, Ichiro Yamane¹, Motohiro Suzuki², Jun Okabayashi³, Seiya Yokokura⁴, Toshihiro Shimada⁴, Taro Nagahama⁴

Affiliations

¹ Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-8628, Japan.
² School of Engineering, Kwansei Gakuin University, Sanda, Hyogo 669-1330, Japan.
³ Research Center for Spectrochemistry, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
⁴ Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan.

Abstract

Co_xFe_3-xO₄(CFO)/Pt bilayers prepared by molecular beam epitaxy were investigated for the anomalous Hall effect and X-ray magnetic circular dichroism (XMCD). We found that the anomalous Hall effect originates from a magnetic proximity effect at the CFO/Pt interface. The XMCD signal in the Pt L-edge was obtained only for the sample deposited at 600 °C, indicating that the magnetic proximity effect is sensitive to the interface structure. Transmission electron microscopy images of the CFO/Pt interface and XMCD measurements of Co and Fe L-edges do not provide direct evidence for interfacial atomic diffusion or alloying. In summary, these results suggest that the magnetic proximity effect is robust for transport properties, such as the anomalous Hall effect, while the induced magnetic moment depends on slight differences in the interfacial structure, such as the presence or absence of interfacial oxygen ions.