1. CNR-NANO, Istituto
Nanoscienze, Centro S3 I-41125 Modena, Italy
2. Department of Physics, North Carolina State University, Raleigh, North Carolina
27695, United States
3. Department
of Chemistry, North Carolina State University, Raleigh, North Carolina
27695, United States
4. Department
of Physics and Department
of Chemistry, University of North Texas, Denton, Texas 76203, United States
5. CSMD, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United
States