1. Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, United States
2. College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
3. Department of Physics, Astronomy, and Materials Science, Missouri State University, Springfield, Missouri 65897, United States
4. Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium
5. Department of Physics, Shahid Rajaee Teacher Training University, Lavizan, Tehran 16788, Iran
6. State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Shanghai 200050, China