1. Department of Materials Science and Engineering, School of Mechanical, Chemical and Materials Engineering, Adama Science and Technology University, Adama, P.O. Box 1888, Ethiopia
2. Department of Applied Physics, School of Applied Natural Science, Adama Science and Technology University, Adama, P.O. Box 1888, Ethiopia
3. Department of Electronics and Communication Engineering, School of Electrical Engineering & Computing, Adama Science and Technology University, Adama, P.O. Box 1888, Ethiopia
4. Departmet of Physics, College of Computational and Natural Science, Addis Ababa University, Addis Ababa, P.O. Box 1176, Ethiopia