**Author details**

Agnes Chinecherem Nkele1 \* and Fabian I. Ezema1,2,3,4

1 Department of Physics and Astronomy, University of Nigeria, Nsukka, Enugu, Nigeria

2 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

3 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

4 Department of Physics, Faculty of Natural and Applied Sciences, Coal City University, Enugu, Nigeria

\*Address all correspondence to: nechenkele@gmail.com

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
