Affiliation: | 1.Department of Metallurgical and Materials Engineering, University of Nigeria, Nsukka, Nigeria ;2.Department of Physics and Astronomy, University of Nigeria, Nsukka, Nigeria ;3.Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West 7129, P.O. Box 722, Somerset West, Western Cape Province, South Africa ;4.UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, P.O. Box 392, Pretoria, South Africa ; |