1. Division of Materials Physics and Center for Spintronics Research Network (CSRN) Graduate School of Engineering Science Osaka University Osaka 560‐8531 Japan
2. Department of Applied Physics The University of Tokyo Tokyo 113‐8656 Japan
3. Faculty of Applied Physics and Mathematics Gdańsk University of Technology Narutowicza 11/12 Gdansk 80‐233 Poland
4. Advanced Materials Center Gdańsk University of Technology Narutowicza 11/12 Gdansk 80‐233 Poland
5. National High Magnetic Field Laboratory 1800 E. Paul Dirac Drive Tallahassee FL 32310 USA
6. Department of Chemistry Princeton University Princeton NJ 08540 USA
7. Department of Chemistry Michigan State University Michigan MI 48824 USA