1. Charles Coulomb (L2C), UMR 5221 CNRS-Université de Montpellier, Montpellier FR 34-095, France
2. Institute of High Pressure Physics, Polish Academy of Sciences, Warsaw PL 01-142, Poland
3. Université Côte d’Azur, CRHEA-CNRS, Rue Bernard Gregory, 06560 Valbonne, France