1. Guangxi Universities Key Laboratory of Non-Ferrous Metal Oxide Electronic Functional Materials and Devices, College of Material Science and Engineering, Guilin University of Technology, Guilin 541004, People’s Republic of China
2. School of Materials Science and Engineering, Nanchang University, Nanchang 330031, People’s Republic of China
3. Department of Mechanical and Construction Engineering, Faculty of Engineering and Environment, Northumbria University at Newcastle, Newcastle upon Tyne NE1 8ST, U.K.