The RuSr2GdCu2O8 (Ru-1212) compound displays weak anti-ferromagnetic ordering with an ordering temperature Tm ∼135K and superconductivity with a transition temperature Tc ∼ 35K. It is quite unusual to identify compounds that show both long-range magnetic ordering and superconductivity. This thesis focuses on the investigation of the Ru-1212 compound with partial substitution of Fe for Cu, i.e. RuSr2Gd(Cu1−xFex)2O8 with x= .00, .01, .02 and .03 by means of measuring the electrical resistivity, magnetization, Seeback effect, thermal conductivity and Mossbauer effect. It was found that the substitution of Fe for ̈ Cu reduced Tc at the rate of 13K per percent of Fe substituted while Tm remains unchanged.
