1. Vereshchagin Institute for High Pressure Physics, Russian Academy of Sciences 1 , 108840 Troitsk, Moscow, Russia
2. Institute of Metallurgy of the Ural Branch of the Russian Academy of Sciences 2 , 620016 Ekaterinburg, Russia
3. Ural Federal University 3 , 620002 Ekaterinburg, Russia
4. Moscow Institute of Physics and Technology 4 , 141701 Dolgoprudny, Russia
5. LSPM-CNRS, Universite Sorbonne Paris Nord 5 , Villetaneuse, France