1. Stanford Institute for Materials and Energy Sciences (SIMES), 2575 Sand Hill Road, Menlo Park, California 94025, USA
2. National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
3. Department of Physics and Astrophysics, University of Delhi, New Delhi 110007, India
4. Department of Physics, Stanford University, Stanford, California 94305, USA
5. Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
6. Department of Applied Physics, Stanford University, Stanford, California 94305, USA
7. Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA
8. Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA