[1] Sri Venkateswara Univ, Dept Phys, Condensed Matter Phys Lab, Tirupati 517502, India
[2] Madanapalle Inst Technol & Sci, Dept Phys, Madanapalle 517325, Andhra Pradesh, India
[3] Kyung Hee Univ, Inst Wearable Convergence Elect, Dept Elect & Informat Convergence Engn, Yongin 17104, Gyeonggi Do, South Korea
[4] CMR Tech Campus, Dept Phys, Nanosensor Res Lab, Medchal Rd, Hyderabad 501401, India
[5] Univ Johannesburg, Dept Phys, Doornfontein Campus, ZA-2006 Johannesburg, South Africa