1. Department of Materials Science and Engineering, The Pennsylvania State University 1 , University Park, Pennsylvania 16802, USA
2. Materials Research Institute, The Pennsylvania State University 2 , University Park, Pennsylvania 16802, USA
3. Department of Physics, North Carolina State University 3 , Raleigh, North Carolina 27695-75, USA
4. Department of Chemical Engineering, The Pennsylvania State University 4 , University Park, Pennsylvania 16802, USA
5. Department of Electrical Engineering, The Pennsylvania State University 5 , University Park, Pennsylvania 16802, USA