1. Center for Basic Research on Materials (CBRM), National Institute for Materials Science (NIMS), Tsukuba, Japan
2. Research Center for Magnetic and Spintronic Materials (CMSM), National Institute for Materials Science (NIMS), Tsukuba, Japan
3. Department of Materials Science and Technology, Tokyo University of Science, Tokyo, Japan
4. Graduate School of System and Information Engineering, University of Tsukuba, Tsukuba, Ibaraki, Japan