1. WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
2. Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
3. Japan Synchrotron Radiation Research Institute (JASRI), Sayo, Hyogo 679-5198, Japan
4. Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, E-50018 Zaragoza, Spain
5. Departamento de Física de la Materia Condensada, Universidad de Zaragoza, E-50009 Zaragoza, Spain
6. Laboratorio de Microscopías Avanzadas, Universidad de Zaragoza, E-50018 Zaragoza, Spain
7. Fundación Instituto de Nanociencia de Aragón (FINA), E-50018 Zaragoza, Spain
8. Research Center for Spectrochemistry, The University of Tokyo, Bunkyo, Tokyo 113-0033,
Japan
9. National Institute for Materials Science, Tsukuba 305-0047, Japan
10. Center for Spintronics Research Network, Tohoku University, Sendai 980-8577, Japan
11. IMDEA Nanociencia, 28049 Madrid,
Spain
12. Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza and Consejo Superior de Investigaciones Científicas, E-50009 Zaragoza, Spain
13. Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan
14. Advanced Science Research Center, Japan Atomic Energy Agency, Tokai 319-1195, Japan