1. Electropyrometallurgy Division, Central Electrochemical Research Institute, Karaikudi 630 006, Tamil Nadu, India; Institute of Physical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany; Department of Physics, Kookmin University, Seoul 136-702, Korea; and Department of Chemistry and Kanbar Laboratory for Nanomaterials, Bar-Ilan University Center for Advanced Materials and Nanotechnology, Bar-Ilan University, Ramat-Gan 52900, Israel