Magnetically driven high-frequency rectification in a cooperative system ofmagnetic tunnel junctions:Frequency dependence

摘要

The effect of magnetically driven high-frequency rectification in a polycrystalline La_0.7Ca_0.3lvInO_3 manganite has been measured at different frequencies of microwave radiation. The magnetic field dependence of a rectified voltage has a broad peak resembling an absorption line, whose shape and position are determined by the radiation frequency. The rectification effect in a polycrystalline manganite sample is related to a ramified network of magnetic tunnel junctions, which is formed by ferromagnetic conducting grains with insulator boundaries. The results of measurements are consistent with a model for the magneto-dependent rectification effect based on the interplay between a spin-polarized current through the tunnel junctions and magnetic resonance induced in the grains forming the junctions.