Room-Temperature Ferromagnetism in Transparent Transition Metal-Doped Titanium Dioxide

American Association for the Advancement of Science (AAAS) - Tập 291 Số 5505 - Trang 854-856 - 2001
Yuji Matsumoto1, Makoto Murakami1, Tomohiro Shono1, Tetsuya Hasegawa1, Tomoteru Fukumura2, M. Kawasaki2, Parhat Ahmet3, Toyohiro Chikyow3,4, Shin‐ya Koshihara5, Hideomi Koinuma6,1,7,3
1Ceramics Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
2Department of Innovative and Engineered Materials, Tokyo Institute of Technology, Yokohama 226-8502, Japan
3National Institute for Research in Inorganic Materials, 1-1 Namiki Tsukuba, Ibaraki 305-0044, Japan
4National Research Institute for Metals, 1-2-1, Sengen, Tsukuba, Ibaraki 305-0047, Japan
5Department of Materials Science, Tokyo Institute of Technology, 2-12-1 Okayama, Meguro-ku, Tokyo, Japan, and Kanagawa Academy of Science and Technology, KSP East Building 301, 3-2-1 Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa, 213-0012, Japan.
6CREST-Japan Science and Technology, Waseda University, 55th Building, 3-4-1 Ohkubo, Shinjyuku-ku 169-8555, Japan.
7Frontier Collaborative Research Center, Tokyo Institute of Technology, Yokohama 226-8503, Japan

Tóm tắt

Dilute magnetic semiconductors and wide gap oxide semiconductors are appealing materials for magnetooptical devices. From a combinatorial screening approach looking at the solid solubility of transition metals in titanium dioxides and of their magnetic properties, we report on the observation of transparent ferromagnetism in cobalt-doped anatase thin films with the concentration of cobalt between 0 and 8%. Magnetic microscopy images reveal a magnetic domain structure in the films, indicating the existence of ferromagnetic long-range ordering. The materials remain ferromagnetic above room temperature with a magnetic moment of 0.32 Bohr magnetons per cobalt atom. The film is conductive and exhibits a positive magnetoresistance of 60% at 2 kelvin.

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Tài liệu tham khảo

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The authors express their thanks for financial support from the Comet project of Science and Technology Agency in Japan as well as from the Japan Society for the Promotion of Science.

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American Association for the Advancement of Science (AAAS)

Tập 291 Số 5505

854-856

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