Enhanced inverse spin Hall contribution at high microwave power levels in La0.67Sr0.33MnO3/SrRuO3 epitaxial bilayers

We have investigated microwave power dependence of dc voltage generated upon ferromagnetic resonance in a La0.67Sr0.33MnO3/SrRuO3 epitaxial bilayer film at room temperature. With increasing microwave power above ∼75 mW, the magnitude of the voltage signal decreases as the sample temperature approaches the Curie temperature of La0.67Sr0.33MnO3 due to heating effects. By analyzing the dependence of the voltage signal on the direction of the magnetic field, we show that with increasing microwave power the contribution from the inverse spin Hall effect becomes more dominant than that from the anisotropic magnetoresistance effect.