1. Centre of Excellence in Solid State Physics, University of the Punjab, Lahore, 54590, Pakistan
2. Institute of Physics, The Islamia University of Bahawalpur, Bahawalpur, 63100, Pakistan
3. State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, R. P. China
4. Department of Physics, Division of Science and Technology, University of Education, Lahore, 54770, Pakistan