1. School of Physics and Optoelectronic Engineering, Ludong University, Yantai, Shandong Province 264000, China
2. The Key Laboratory of Chemical Metallurgy Engineering of Liaoning Province and School of Materials and Metallurgy, University of Science and Technology Liaoning, Anshan, Liaoning Province 114051, China
3. School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
4. School of Materials Science and Engineering, Ocean University of China, Qingdao 266100, P. R. China
5. Department of Physics, College of Science, University of Jeddah, Jaddah 23218, Saudi Arabia