1. Department of Physics, University of the Free State, P. O. Box 339, Bloemfontein 9300, South Africa
2. Extreme Light Infrastructure-Nuclear Physics (ELI-NP), ‘Horia Hulubei’ National R&D Institute for Physics and Nuclear Engineering (IFIN-HH), 077125 Măgurele, Ilfov, Romania
3. Centre for HRTEM, Nelson Mandela University, Port Elizabeth, 6001, South Africa