1. Department of Physics, Abdul Kalam Research Center, Sacred Heart College, Tirupattur, Tamilnadu, India 635 601
2. Deparment of Physics, Presidency College, Chennai, Tamilnadu, India 600 005
3. Department of Physics, Kings Engineering College, Sriperumbudur, Chennai, Tamilnadu, India 602 117
4. Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankulathur, Chennai, India 603 203
5. Nanotechnology Research Center (NRC), SRM Institute of Science and Technology, Kattankulathur, Chennai, India 603 203