1. Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
2. Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan
3. Key Lab of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China
4. Laboratoire ICube, CNRS-Université de Strasbourg, 67037 Strasbourg, France
5. Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802, USA