Hysteresis and stepwise structure in MR curves of granular superconducting ruthenocuprates RuSr2(Gd1.5Ce0.5)Cu2O10−δ

► Granular superconductivity in a polycrystalline RuSr2(Gd1.5Ce0.5)Cu2O10 are studied. ► Current and magnetic-field dependences of resistive transition to superconducting state. ► Current dependences of differential resistance taken at different temperatures demonstrate crossing point effect. ► Two types of MR hysteresis (clockwise and anticlockwise) have been found depending on temperature. ► Stepwise structure in MR hysteretic curves has been observed and explained.