Aisha salih Ahmed ezzalldeen2017-10-292017-10-292015http://hdl.handle.net/123456789/64974 ACKNOWLEDGEMENTS First, I thank the God for giving me power to complete this research. Then: I have to thank my parents, whom continue to grow, learn and develop and whom have been a source of encouragement and inspiration to me throughout my life. I express my deepest sense of reverence and gratitude to my sister Fatima and Abeer sincerely to thank my supervisor, Dr. Mohamed Ahmed Siddig, and co-supervisor Dr.Eltayeb Musa Mustafa for his great patient, constructive criticisms, and myriad useful suggestion apart from invaluable guidance and support throughout this study. I would also like to thank Dr. Mohammed Ibrahim Mohammed. I learned from his insight a lot. Also, I would like to thank all the staff of Physics department, college of science, Alneelain University. I express my heartfelt gratefulness for their support that I believed I learned from the best. To all my friends, thank you for your understanding and encouragement. Your friendship makes my life a wonderful experience. I cannot list all the names here, but you are always on my mind.cadmium sulfideThesis