1. Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48201, United States
2. Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
3. Department of Materials Science and Engineering, The University of Tennessee, Knoxville, Tennessee 37996, United States
4. Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
5. Department of Electrical and Computer Engineering, Wayne State University, Detroit, Michigan 48202, United States
6. Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States