Hall effect in a GdBa2Cu3O7−δ/La0.75Sr0.25MnO3 perovskite bilayer

We present results on the Hall coefficient RH in the normal state for a GdBa2Cu3O7−δ/La0.75Sr0.25MnO3 bilayer and a La0.75Sr0.25MnO3 film grown by dc magnetron sputtering on (1 0 0) SrTiO3. We find that the electric transport on the bilayer can be qualitatively described using a simple parallel layers model. The GdBa2Cu3O7−δ layer presents a carrier density approximately equal to that reported for 7 − δ = 6.85 oxygen doping. Also we observe an unexpected presence of two Hall resistivity regimes, effects that may be associated with the internal magnetic field induced on the superconducting layer by the ferromagnetic layer.