**Author details**

Jagannathan Thirumalai1\*, Venkatakrishnan Mahalingam1 and Rajagopalan Krishnan2

\*Address all correspondence to: thirumalaijg@gmail.com; jthirumalai@bsauniv.ac.in

1 Department of Physics, School of Physical and Chemical Sciences, B. S. Abdur Rahman University, Vandalur, Chennai, Tamil Nadu, India

2 Department of Physics, Rajalakshmi Institute of Technology, Kuthambakkam, Chennai, Tamil Nadu, India
