1. School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
2. Facility for Analysis, Characterisation, Testing and Simulation (FACTS), Nanyang Technological University, Singapore 639798, Singapore
3. Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
4. IPIT & Department of Physics, Jeonbuk National University, Jeonju 54896, South Korea