Ferromagnetic and FMR properties of the YIG/TiO2/PZT structures obtained by ion-beam sputtering

Abstract For the first time, the YIG (2 μm) /TiO2 (0.2 μm) /PZT (400 μm) structures, where YIG is a polycrystalline layer of yttrium-iron garnet (Y3Fe5O12), PZT is an epitaxially mismatched ferroelectric ceramics based on lead zirconate titanate (PbZr0.45Ti0.55O3) were synthesized by means of ion-beam sputtering - deposition technique. Scanning electron microscopy combined by focused ion-beam method indicates the presence of high-quality plane-parallel YIG/TiO2 and TiO2/PZT interfaces. They were obtained by preliminary ion-beam planarization of the substrate surface using an anti-diffusion layer of titanium dioxide TiO2. Atomic force microscopy showed that planarization allows to achieve a surface smoothness of 10 nm. FMR spectroscopy revealed that the ferrite garnet layers are characterized by a resonance absorption linewidth of ∼100 Oe. The linewidth broadening is due to the presence of defects and YIG layer roughness because of the substrate imperfection. The calculated values of the spin-wave damping parameter are of the order of 10-3. The obtained YIG/TiO2/PZT structures can serve as media for the spin waves propagation.