1. State Key Laboratory of High Performance Ceramics and Superfine MicrostructureShanghai Institute of CeramicsChinese Academy of Sciences 1295 Dingxi Road Shanghai 200050 P. R. China
2. Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of Sciences 19A Yuquan Road Beijing 100049 P. R. China
3. Shanghai Synchrotron Radiation FacilityZhangjiang Laboratory 239 Zhangheng Road Shanghai 201204 P. R. China