1. Department of Materials Science and Engineering, KAIST, Daejeon 34141, South Korea
2. Department of Physics, University of Ulsan, Ulsan 44610, South Korea
3. Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
4. Spin Engineering Physics Team, Division of Scientific Instrument, KBSI, Daejeon 34133, South Korea
5. Japan Synchrotron Radiation Research Institute (JASRI), Sayo, Hyogo 679-5198, Japan
6. Center for Spintronics Research Network (CSRN), Graduate School of Engineering Science, Osaka University, Osaka 560-8531, Japan
7. Department of Materials Science and Engineering, Korea University, Seoul 02841, South Korea
8. KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, South Korea