[1] Univ South Africa UNISA, UNESCO UNISA Africa Chair, Nanosci Nanotechnol Labs, Coll Grad Studies, POB 392, Pretoria, South Africa
[2] iThemba LABS Natl Res Fdn NRF, MRG, Nanosci African Network NANOAFNET, 1 Old Faure Rd,POB 722, ZA-7129 Somerset West, Western Cape Pr, South Africa
[3] Bharathiyar Univ, Ctr Res & Dev, Coimbatore 641046, Tamil Nadu, India
[4] Auxilium Coll Autonomous, PG Res & Dept Chem, Vellore, Tamil Nadu, India
[5] St Xaviers Coll Autonomous, Dept Chem, Tirunelveli 627002, India
[6] Loyola Coll Autonomous, Dept Chem, LIFE, Madras 600034, Tamil Nadu, India
[7] SBM Coll Engn & Technol, Dept Phys, Dindigul 624005, India
[8] Khadir Mohideen Coll, Dept Phys, Adirampattinam 614601, India
[9] Natl Isotope Ctr, GNS Sci, POB 31312, Lower Hutt 5010, New Zealand