1. Center for Materials
for Information Technology, University of Alabama, Box 870209, 2007 Bevill Building, Tuscaloosa, Alabama 35487, United States
2. Department of Physics, Fergusson College, Savitribai Phule Pune University, Pune, India
3. Department of Chemistry, University of Alabama, Box 870336, 250 Hackberry Lane, Tuscaloosa, Alabama 35487-0336, United States