1. Department of Physics and Astronomy University of Nigeria Nsukka Nsukka Nigeria
2. College of Graduate Studies University of South Africa (UNISA) Pretoria South Africa
3. Nanosciences African Network (NANOAFNET), iThemba LABS National Research Foundation Somerset West South Africa
4. National Core Research Centre for Hybrid Materials Solution Pusan National University Busan Republic of Korea
5. Department of Physics and Astronomy University of Western Ontario London Ontario Canada
6. Department of Science and Technology Shivaji University Kolhapur India
7. Department of Physics, Faculty of Natural and Applied Sciences Coal City University Enugu Nigeria