1. Department of Physics, University of South Florida, Tampa, FL, 33620, USA
2. Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, 01062 Dresden, Germany
3. Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
4. Material Measurement Laboratory, National Institute of Standards and Technology Gaithersburg, MD 20899, USA
5. Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA