1. Center for High Pressure Science and Technology Advanced Research, Beijing, China
2. Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, Germany
3. Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping, Sweden
4. Material Physics and Technology at Extreme Conditions, Laboratory of Crystallography, University of Bayreuth, Bayreuth, Germany