[1] Pondicherry Univ, Ctr Nanosci & Technol, Kalapet 605014, Puducherry, India
[2] Indira Gandhi Ctr Atom Res, Div Mat Phys, Mat Sci Grp, Kalpakkam 603102, Tamil Nadu, India
[3] Indira Gandhi Ctr Atom Res, Mat Sci Grp, Surface & Nanosci Div, Kalpakkam 603102, Tamil Nadu, India