The results of studies of ferromagnetic resonance (FMR) of iridate/manganite epitaxial heterostructures in a wide range of microwave frequencies (1-20 GHz) are presented. The magnitudes of imaginary and real parts of the spin mixing conductance of the heterostructure boundary determin-ing the spin current were determined from the frequency dependence of the spin damping and changes in the resonance field of the FMR. It is shown that the value of the imaginary part of spin conductance is comparable to the real part, which may be caused by strong spin-orbit interaction present in 5d-oxides of transition metals (iridate).

The temperature dependence of the voltage induced by the spin current was studied in an epitaxial thin-film La0.7Sr0.3MnO3 / SrIrO3 heterostructure deposited on a single-crystal NdGaO3 substrate. The spin current was generated by microwave pumping under conditions of ferromagnetic resonance in the La0.7Sr0.3MnO3 ferromagnetic layer and was detected in the SrIrO3 layer due to inverse spin Hall effect. A significant increase of half-width of the spin current spectrum along with the rise of amplitude of the spin current upon cooling from room temperature (300 K) to 135 K were observed.

A numerical study of the features of the propagation of spin waves in a waveguide made of yttrium iron garnet (YIG) and Fe-Rh alloy in the form of a plate, located on top of the central part of the YIG, is carried out. Based on the simulation results, the possibilities of controlling the dynamics of spin waves in the structure under study were also revealed. Micromagnetic numerical simulation was used to study the transfer of a spin-wave signal in a multimode mode by numerically solving the Landau – Lifshitz – Hilbert equation. Transformation of the transmission spectra of spin waves shows that the proposed structure will make it possible to control the propagation of spin-wave modes due to a sharp change in the Fe-Rh magnetization in the region of the magnetic phase transition temperature close to room temperature. In addition, the spin wave signal can be controlled by a small temperature change in the Fe-Rh plate generated by the laser radiation. The two-layer structure of YIG / Fe-Rh, from an applied point of view, can be used as a functional unit in planar magnon networks performing space-frequency demultiplexing and filtering of spin-wave modes.