We have started the research on ‘spin-filter’devices applicable for future storage or switching devices. Using these devices, we will be able to utilize not only electron charges but electron spin states. The adoption of half-metallic materials, such as Fe3O4, as the ferromagnetic layers in magnetic tunneling junctions is an attractive approach for realizing ‘spin-filter’ devices with large spin polarization.
[Fe3O4/ Ru] films were deposited using a dual ion beam sputtering method at room temperature. Highly crystalline [Fe3O4/ Ru] films could be obtained by tuning the Kr ion beam energy to exactly 160 eV during the film deposition. We have succeeded in fabricating 100-nm-dimension [Co-Fe/Al-O/Fe3O4] pillar structures using electron beam lithography and ion beam milling processes. Barrier heights for these pillars of approximately 2.6 eV are attained when the pillar size is larger than 120 nm.
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|Dr. Yasuyoshi MIYAMOTO
He received the B.S., M.S. and Ph.D. degrees in physical electronics from Tokyo Institute of Technology in 1993, 1995 and 1998, respectively. He was a research fellow of the Japan Society for the Promotion of Science (JSPS) from 1996 to 1998. He joined NHK in 1998 and has been with NHK Science and Technical Research Laboratories. He was also a visiting scholar at Stanford University, California, from 2001 to 2002. He has been engaged in the magnetic materials and magnetic thin-film devices for recording and the fundamental research on spin-electronics. He is a member of the Institute of the Electrical and Electronics Engineers (IEEE) and the Magnetics Society of Japan (MSJ).
Mr. Hirotaka SHIINOHe received the B.S. and M.S. degrees in engineering science and fundamental energy science from the Kyoto University in 1998 and 2000, respectively. He joined NHK in 2000. Since 2003, he has been with NHK Science and Technical Research Laboratories. He has been engaged in the researching on spin-tunneling devices and related materials.
|Mr. Kiyoshi KUGA
He received the B.S. and M.S. degrees in electrical engineering from Waseda University, Tokyo, in 1981 and 1983, respectively. He joined NHK in 1983. Since 1986, he has been with NHK Science and Technical Research Laboratories. He has been engaged in the researching on the perpendicular magnetic recording media, and fundamental research on spin-electronics including ferromagnetic semiconductors and spin-filter devices. He is currently a senior research engineer of materials science division. He is a member of the Magnetics Society of Japan (MSJ), the Japan Society of Applied Physics (JSAP) and the Institute of Image Information and Television Engineers of Japan (ITE).