1. Department of Textile Science, Nelson Mandela University, Summerstrand, Port Elizabeth, South Africa
2. Council for Scientific and Industrial Research (CSIR) (Materials Science and Manufacturing), Summerstrand, Port Elizabeth, South Africa
3. Department of Physics, Nelson Mandela University, Summerstrand, Port Elizabeth, South Africa
4. Centre for High Resolution Transmission Electron Microscopy (CHRTEM), University Way, Summerstrand, Port Elizabeth, South Africa
5. School of Physics and Microscopy and Microanalysis Unit, University of Witwatersrand, Johannesburg, South Africa