Application the Ion Beam Sputtering Deposition Technique for the Development of Spin-Wave Structures on Ferroelectric Substrates

The microwave properties of structures in the form of the 2 μm iron-yttrium garnet (YIG) films, grown by the ion beam sputtering deposition method on epitaxially mismatched substrates of ferroelectric ceramics based on lead zirconate titanate (PZT, PbZr0.45Ti0.55O3), are discussed. The obtained structures were formed and pre-smoothed by the ion beam planarization substrates with the use of an anti-diffusion layer of titanium dioxide TiO2. The atomic force microscopy showed that the planarization of the substrates allows for reaching a nanoscale level of roughness (up to 10 nm). The presence of smooth plane–parallel interfaces of YIG/TiO2 and TiO2/PZT is evidenced by scanning electron microscopy performed in focused gallium ion beams. Ferromagnetic resonance spectroscopy revealed a broadening in the absorption line of the ferrite garnet layers in the resonance ≈ 100 Oe. This broadening is associated with the presence of defects caused by the of the ceramic substrate non-ideality. The estimated damping coefficient of spin waves turned out to be ~10−3, which is two orders of magnitude higher than in an ideal YIG single crystal. The YIG/TiO2/PZT structures obtained can be used for the study of spin waves

Interface magnetoelectric effect in the layered heterostructures with Co layers on the polished and ion-beam planarized ceramic PZT substrates

The low-frequency room temperature interface magnetoelectric (ME) effect was observed in the layered heterostructures comprising the ferromagnetic (FM) Co layers and ferroelectric (FE) ceramic substrates on the base of lead zirconate titanate PbZr0.45Ti0.55O3 (PZT). The Co films 1–12 μm in thickness were deposited by ion-beam sputtering/deposition technics onto the 400 μm PZT substrates. Results of X-ray, magnetic and ME experiments have shown the existence of ME effect in Co/PZT/Co and (Co/PZT/Co)3 heterostructures obtained by the above mentioned techniques being independent on ferromagnetic/ferroelectric interface roughness. The values of ME voltage coefficient in heterostructures with ion-beam planarized PZT surfaces are much higher than that in heterostructures with mechanochemically polished ceramic substrate surfaces. The heterostructures possess ME effect of the same order as those obtained by means of the mechanical bonding of FM and FE sheets with organic binders and have the typical ME hysteresis curves. The structures obtained are perspective for application as energy-independent elements in magnetic field sensors and magnetic memory