1. Soochow University-Western University Center for Synchrotron Radiation Research and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, 199 Ren-Ai Road, Suzhou 215123, P.R. China
2. Institut für
Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, D-72076 Tübingen, Germany
3. Institut für Physik, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 6, D-12489 Berlin, Germany
4. Department of Materials and Science, Iwate University, Ueda 4-3-5, Morioka, Iwate 020-8551, Japan
5. European Synchrotron Radiation Facility, BP 220, 38043 Grenoble Cedex 9, France
6. Graduate School of Advanced
Integration Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan