1. Department of Chemistry Bar-Ilan University Ramat-Gan 5290002 Israel
2. Department of Materials Science & Engineering Drexel University Philadelphia PA 19104-2875 USA
3. Department of Mechanical Engineering & Mechanics Drexel University Philadelphia PA 19104-2875 USA
4. Department of Electrical & Computer Engineering Drexel University Philadelphia PA 19104-2875 USA
5. Department of Materials Science & Engineering University of California at Berkeley Berkeley CA 94720 USA
6. Materials Sciences Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
7. Department of Physics Drexel University Philadelphia PA 19104-2875 USA