1. a School of Metallurgical and Materials Engineering, Chongqing University of Science and Technology , Chongqing , 401331 , China
2. b College of Materials Science and Engineering, Chongqing University , Chongqing , 400044 , China
3. c State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China , Chengdu , 610054 , China