Affiliation: | 1. Nanosciences African Network (NANOAFNET), Materials Research Department, iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Somerset West, Western Cape Province, South Africa;2. Physics Dept., University of Western Cape, Bellville, 7535 Cape Town, South Africa;3. National Centre for Nanostructured Materials, Council for Scientific and Industrial Research, PO Box 395, Pretoria 0001, South Africa;4. UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk ridge, PO Box 392, Pretoria, South Africa |