Material that possesses both magnetic and electric properties has been demanded the magneto-electric applications such as sensors and tunable devices. We have studied the tunneling magneto-resistance (TMR) effect and tunneling magneto-dielectric (TMD) properties of nano-composite films that consist of magnetic nanometer-sized metal granules and an insulator matrix. The purposes of this study are to reveal the relationship between the microstructures, physical properties and these TMR and TMD effects in Co-oxide nano-composite films. We have selected ferromagnetic Co as granules, and oxide as insulator matrix owing to its high electric resistivity and good thermal stability. The maximum TMR ratios of Co- Al2O3 film was 8.2%. Interestingly, the Co content of the maximum TMR ratio in each film roughly corresponds with the Co content which shows electric resistivity of around 106μΩ･cm. On the Co- Al2O3 films, dielectric enhancement due to granule pairs were observed at Co content of 17 - 26 at%. Annealing makes the granule size larger and the magnetic-field sensitivity improved. Acknowledgments This work was supported by Moe Kimura, Hanae AOKI, Yang CAO, Nobukiyo KOBAYASHI, and Shigehiro OHNUMA. References Materials Transactions, 2022, 63(12), pp. 1677–1681. ―116―(Advanced Interdisciplinary Research Division/Materials and Energy Platform, FRIS) Hiroshi MASUMOTO 本章に本研究所を本務とする教員の研究成果概要、および令和4年度に終了した公募研究課題の研究成果概要をまとめる。なお、本報告書作成時に転出している教員については、掲載されていない場合がある。８．令和4年度研究成果概要 8.1 先端学際基幹研究部 ８．１ 先端学際基幹研究部 Preparation of Co-Oxide nano-composite films and their magneto-electric effects ８．令和4年度研究成果概要
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