1. Department
of Physics and Astronomy, University of Utah, 115S 1400E, Salt Lake City, Utah 84112, United States
2. Department
of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
3. Quantum
Condensed Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
4. High
Pressure Collaborative Access Team (HPCAT), Geophysical Laboratory, Carnegie Institute of Washington, Argonne, Illinois 60439, United States