1. Department of Physics, Bharathiar University, Coimbatore 641 046, India
2. Department of Nanomaterials
Engineering, Chungnam National University, Daejeon 305-764, South Korea
3. Department of Nanoscience and
Technology, Bharathiar University, Coimbatore
641 046, India
4. Department
of Chemical and Materials
Engineering, Lunghwa University of Science and Technology, Taoyuan, Taiwan