1. Department of Physics, Govt Post Graduate College Berinag Pithoragarh, India
2. Guangdong Provincial Key Laboratory of Nuclear Science, Institute of Quantum Matter, South China Normal University, Guangzhou 510006, P. R. China
3. Guangdong-Hong Kong Joint Laboratory of Quantum Matter, Southern Nuclear Science, Computing Center, South China Normal University, Guangzhou 510006, P. R. China
4. D.S.B. Campus, Kumaun University, Nainital 263001, India