[1] Lanzhou Univ, Key Lab Magnetism & Magnet Mat, Minist Educ, Sch Phys Sci & Technol, Lanzhou 730000, Peoples R China
[2] Lanzhou Univ, Electron Microscopy Ctr Lanzhou Univ, Lanzhou 730000, Peoples R China
[3] Baotou Res Inst Rare Earths, State Key Lab Baiyunobo Rare Earth Resource Res &, Baotou 014030, Peoples R China
[4] Karakorum Int Univ, Dept Phys, Gilgit Baltistan 15100, Pakistan