1. Herbert Gleiter Institute of Nanoscience School of Materials Science and Engineering Nanjing University of Science and Technology Nanjing 210094 P. R. China
2. Department of Applied Physics and Institution of Energy and Microstructure Nanjing University of Science and Technology Nanjing 210094 P. R. China
3. Physikalisches Institute Westfälische Wilhelms‐Universität Münster 48149 Münster Germany
4. Center for Nanotechnology (CeNTech) Heisenbergstrasse 11 48149 Münster Germany