Reduced magnetocrystalline anisotropy of CoFe2O4 thin films studied by angle-dependent x-ray magnetic circular dichroism

Yosuke Nonaka; Yuki K. Wakabayashi; Goro Shibata; Shoya Sakamoto; Keisuke Ikeda; Zhendong Chi; Yuxuan Wan; Masahiro Suzuki; Tsuneharu Koide; Masaaki Tanaka; Ryosho Nakane; Atsushi Fujimori

doi:10.1063/5.0057576

AIP Advances (Aug 2021)

Reduced magnetocrystalline anisotropy of CoFe2O4 thin films studied by angle-dependent x-ray magnetic circular dichroism

Yosuke Nonaka,
Yuki K. Wakabayashi,
Goro Shibata,
Shoya Sakamoto,
Keisuke Ikeda,
Zhendong Chi,
Yuxuan Wan,
Masahiro Suzuki,
Tsuneharu Koide,
Masaaki Tanaka,
Ryosho Nakane,
Atsushi Fujimori

Affiliations

Yosuke Nonaka: Department of Physics, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
Yuki K. Wakabayashi: Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
Goro Shibata: Department of Physics, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
Shoya Sakamoto: Department of Physics, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
Keisuke Ikeda: Department of Physics, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
Zhendong Chi: Department of Physics, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
Yuxuan Wan: Department of Physics, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
Masahiro Suzuki: Department of Physics, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
Tsuneharu Koide: Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
Masaaki Tanaka: Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
Ryosho Nakane: Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
Atsushi Fujimori: Department of Physics, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan

DOI: https://doi.org/10.1063/5.0057576
Journal volume & issue: Vol. 11, no. 8
pp. 085317 – 085317-5

Abstract

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Spinel-type CoFe2O4 is a ferrimagnetic insulator with the Néel temperature exceeding 790 K, and it shows strong cubic magnetocrystalline anisotropy (MCA) in bulk materials. However, when a CoFe2O4 film is grown on other materials, its magnetic properties are degraded so that so-called magnetically dead layers are expected to be formed in the interfacial region. We investigate how the magnetic anisotropy of CoFe2O4 is modified at the interface of CoFe2O4/Al2O3 bilayers grown on Si(111) using x-ray magnetic circular dichroism. We find that the thinner CoFe2O4 films have significantly smaller MCA values than bulk materials. The reduction in MCA is explained by the reduced number of Co2+ ions at the Oh site, as reported by a previous study [Wakabayashi et al., Phys. Rev. B 96, 104410 (2017)].

Published in AIP Advances

ISSN: 2158-3226 (Online)
Publisher: AIP Publishing LLC
Country of publisher: United States
LCC subjects: Science: Physics
Website: http://aipadvances.aip.org/

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