1. Department of Physics, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
2. Institute of High Pressure Physics Polish Academy of Sciences, Sokolowska, 29/37, 01-142 Warsaw, Poland
3. Center for Integrated Research of Future Electronics, Institute of Materials and Systems for Sustainability, Nagoya University, C3-1 Furo-cho, Chikusa-su, Nagoya 464-8603, Japan