*Vaclav Kubecek1, Michal Jelinek1, Miroslav Cech1, David Vyhlidal1, Fengkai Ma2, Dapeng Jiang2, Liangbi Su2
(1. Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering, 2. 2CAS Key Laboratory of Transparent and Opto-functional Inorganic Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences)