Asfaw, Mesfin2018-06-292023-11-092018-06-292023-11-092006-07http://10.90.10.223:4000/handle/123456789/4996This work focuses on the study of co-existence of superconductivity and ferromagnetism in general and in UGe2 superconductor in particular. Starting with a model Hamiltonian for the system and using Green functions formalism, we obtain expressions for Tc and superconductivity and magnetic order parameters and respectively. For suitable value of the parameters the phase diagram is obtained which shows the possibility of the co-existence of superconductivity and ferromagnetism in UGe2. keywords: Superconductivity (SC), Ferromagnetism (FM), Co-existence, Green functionsenSuperconductivity and Ferromagnetism in UGE2Thesis