1. Conditions Extrêmes et Materiaux: Haute Température
et Irradiation, CEMHTI, UPR 3079, CNRS, Université Orleans, 45071 Orléans, France
2. Department of Molten Systems, Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 36 Bratislava, Slovakia