A joint research group led by Professor Shinobu Ohya and Professor Masaaki Tanaka has fabricated a planer 2-terminal device consisting of a ferromagnet/semiconductor/ferromagnet structure, which is the basis of spin transistors, using single-crystal oxides and achieved a large magnetoresistance ratio of over 140%, more than 10 times larger than conventional devices at a practical level. The key point is that the device was fabricated by ion implantation without damaging the crystallinity of the single crystal oxide. 3-terminal devices were also fabricated, and current modulation was successfully achieved by gate voltage. It is expected to be realized as an energy-saving spin transistor that has both a transistor function and a nonvolatile memory function that can retain memory for a long period of time without power supply. The paper was published in the online edition of “Advanced Materials” on May 30.
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