1. Department of Electrical and Computer Engineering, The Ohio State University 1 , Columbus, Ohio 43210, USA
2. NanoSystems Laboratory, Department of Physics, The Ohio State University 2 , Columbus, Ohio 43210, USA
3. Materials and Manufacturing Directorate, Air Force Research Laboratory 3 , 2179 12th Street, B652/R122WPAFB, Ohio 45433-7718, USA
4. UES 4 , 2179 12th St., Wright-Patterson Air Force Base, Dayton, Ohio 45433, USA
5. Department of Materials Science and Engineering, The Ohio State University 5 , Columbus, Ohio 43210, USA