[1] Shivaji Univ, Dept Phys, Thin Film Mat Lab, Kolhapur 416004, Maharashtra, India
[2] Bhabha Atom Res Ctr, Div Chem, Trombay Mumbai 85, India
[3] Shivaji Univ, Dept Chem, Mat Res Lab, Kolhapur 416004, Maharashtra, India
[4] Natl Dong Hwa Univ, Dept Phys, Hualien 97401, Taiwan