[1] GVM Girls Coll, Electroceram Res Lab, Sonepat 131001, India
[2] PG Hindu Coll, Dept Phys, Sonepat 131001, India
[3] GVM Girls Coll, Dept Phys, Sonepat 131001, India
[4] Thapar Univ, Sch Phys & Mat Sci, Patiala 147004, Punjab, India
[5] Natl Phys Lab, New Delhi 110012, India
[6] Solid State Phys Lab, Delhi 110054, India