1. School of Materials
Sciences and Engineering, University of Science and Technology Beijing, Beijing 100083, China
2. Laboratory of
Crystal Physics, Kirensky Institute of Physics, SB RAS, Krasnoyarsk 660036, Russia
3. Far Eastern State Transport University, Serysheva str. 47, Khabarovsk 680021, Russia
4. School of Materials
Science and Engineering, Chonnam National University, 300, Yongbong-dong, Buk-gu, Gwangju 500-757, South Korea