[1] Department of Physics, National Institute of Technology, Patna,800 005, India
[2] Materials Research Laboratory, Department of Physics, A N College, Patna,800013, India
[3] Thin Film Magnetism Group, SVSM/PLD laboratory, UGC-DAE-CSR Indore, University Campus, Khandwa Road, M.P., Indore,452001, India
[4] Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai,400094, India
[5] Institute of Physics, University of Silesia, Uniwersytecka 4, Katowice,40-007, Poland