1. Materials Research Institute and Department of Materials Science & Engineering The Pennsylvania State University University Park PA 16802 USA
2. State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Shapingba District Chongqing 400044 P. R. China
3. CNRS University of Bordeaux ICMCB UMR 5026 F‐33600 Pessac France