1. Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, School of Materials Science and Engineering, Nankai University, 300350 Tianjin, China
2. Department of Physics, University of Basel, 4056 Basel, Switzerland
3. Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain
4. State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, 730000 Lanzhou, China
5. M. Smoluchowksi Institute of Physics, Jagiellonian University in Krakow, 30-348 Krakow, Poland