1. Key Laboratory of Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou 730000, P. R. China
2. Qinghai Provincial Key Laboratory of New Light Alloys, Qinghai Provincial Engineering Research Center of High Performance Light Metal Alloys and Forming, Qinghai University, Xining 810016, PR China
3. King Abdullah University of Science and Technology (KAUST), Physical Science and Engineering (PSE) Division, Thuwal 23955-6900, Saudi Arabia
4. School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070, PR China
5. School of Life Science and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou 730000, P. R. China
6. Department Physics, Karakorum International University Gilgit-Baltistan 15100, Pakistan
7. Key Lab of Mineral Resources in Western China (Gansu), School of Earth Sciences, Lanzhou University, Lanzhou 730000, China