[1] VIT, Sch Adv Sci, Dept Phys, Vellore 632014, Tamil Nadu, India
[2] VIT, Ctr Crystal Growth, Thin Films Lab, Vellore 632014, Tamil Nadu, India
[3] Akita Univ, Ctr Reg Revitalizat Res & Educ, Akita 0108502, Japan
[4] VIT AP, Dept Phys, Amaravati 522237, Andhra Pradesh, India
[5] VIT, Ctr Nanotechnol Res, Vellore 632014, Tamil Nadu, India
[6] Sungkyunkwan Univ, Sch Adv Mat Sci & Engn, Gyeonggi 16419, South Korea
[7] Sungkyunkwan Univ, Dept Phys, Suwon 440746, South Korea
[8] Sungkyunkwan Univ, Sungkyunkwan Adv Inst Nanotechnol SAINT, Suwon 440746, South Korea
[9] Indira Gandhi Ctr Atom Res, Mat Phys Div, Kalpakkam 603102, Tamil Nadu, India