Cuprate oxides (n-type) with the chemical formula    and Fe;  and 0.1) were synthesized by the conventional ceramic method. The lattice parameters were increased for the substituted samples. The magnetic transition temperature of Cu ions is affected by the substitution. The electrical resistivity is decreased for the substituted samples relative to the pure Gd-cuprate oxide sample. The majority of the charge carriers are electron for substituted Gd-cuprate oxide. The novel of this study is the increase of the stability of Gd substituted cuprate oxide with ions of smaller ionic radii than Gd one and the disappearance of week ferromagnetic compound around the room temperature.

cuprate oxides, stability factor, electrical properties, transition temperature.