The Coexistence of Superconductivity and Ferromagnetism in RuSr2GdCu2O8

Abstract

This work focuses on the theoretical investigation of the possible coexistence of super conductivity and ferromagnetism in RuSr2GdCu2O8. By developing a model Hamilto nian for the given system and by using the Green’s function formalism, we have been ob tained expressions for superconducting transition temperature Tc, magnetic transition temperature (Tm), superconducting order parameter (∆) and magnetic order parame ter (η).By using the experimental and theoretical values and by considering plausible approximations of the parameters in the obtained expressions, we plot the phase di agrams of superconducting transition temperature (Tc) versus superconducting order parameter (∆), superconducting transition temperature (Tc) versus magnetic ordering parameter (η) and magnetic transition temperature (Tm) versus magnetic ordering pa rameter (η). Finally, by merging the phase diagrams of superconducting transition temperature (Tc) versus magnetic order parameter (η) and magnetic transition temper ature (Tm) versus magnetic order parameter (η).The region under the intersection of the two merged graphs shows that coexistence of superconductivity and ferromagnetism in RuSr2GdCu2O8.Our finding indicates that both states coexist below superconducting transition temperature (Tc ≈ 37K).