1. Center for High Pressure Science and Technology Advanced Research, Pudong, Shanghai 201203, People’s Republic of China
2. Department of Physics and Astronomy, George Mason University, Fairfax, Virginia 22030, USA
3. Department of Geological Sciences, Stanford University, Stanford, California 94305, USA
4. Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
5. Jiangsu Key Laboratory of Advanced Metallic Materials, School of Materials Science and Engineering, Southeast University, Nanjing 211189, People's Republic of China