Damping of longitudinal and shear acoustic waves in a structure with ZnO films with straight and inclined textures

We have reported on the results of an investigation of the damping of longitudinal and shear hyperacoustic waves in Al/ZnO/Al/ZnO/YAG structures (lutetium-doped yttrium–aluminum garnet) based on ZnO piezo-active films with straight and inclined textures, which are synthesized at substrate temperatures $T\approx$ 25–400$^\circ$C in an unbalanced planar magnetron sputtering system. It has been shown that anomalously high values of damping up to 45 dB is observed for the passage of acoustic waves through ZnO films with straight textures, which are grown at a substrate temperature $T\approx$ 200–300$^\circ$C; an increase in the deposition temperature to $T\approx$ 400$^\circ$C leads to a decrease in the introduced acoustic losses by 30–40 dB.