1. Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433
2. University of Dayton Research Institute (UDRI), University of Dayton, Dayton, Ohio 45469
3. Department of Physics, Department of Chemistry, and Richard E. Smalley Institute for Nanoscale Science and Technology, Rice University, Houston, Texas 77251
4. School of Materials Engineering, and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907