1. Key Laboratory of Transparent Opto‐Functional Inorganic Materials of Chinese Academy of Sciences, Shanghai Institute of Ceramics, 1295 Dingxi Road, Shanghai 200050, P. R. China, Fax: +86‐21‐5243122
2. Graduate School of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100039, P. R. China
3. Northwest Institute for Nonferrous Metal Research, 96 Weiyang Road, Xi'an 710016, Shaanxi, P. R. China
4. Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, P. R. China
5. Max‐Planck‐Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, Dresden 01187, Germany