1. Materials Research Laboratory, Department of Physics, Indian Institute of Technology Indore 1 , Simrol, Khandwa Road, Indore 453552, India
2. Department of Physics, Indian Institute of Technology Kanpur 2 , Kanpur 208016, India
3. Department of Mathematics, The Pennsylvania State University-Altoona College 3 , Altoona, Pennsylvania 16601, USA
4. Department of Physics, The Pennsylvania State University-Altoona College 4 , Altoona, Pennsylvania 16601, USA
5. Materials Research Institute, The Pennsylvania State University 5 , University Park, Pennsylvania 16802, USA