1. School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA
2. Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
3. CEA-LITEN, 17 Rue des Martyrs, Grenoble 38054, France
4. Université de Lorraine, LEMTA, UMR7563, CNRS, F-54506 Vandoeuvre Les Nancy, France
5. Department of Mechanical and Materials Engineering, University of Cincinnati, Cincinnati, Ohio 45221, USA
6. School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907, USA
7. Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA