Using a high-resolution X-Ray diffraction measurement method, the surface acoustic waves (SAW) propagation in a graphene film on the surface of a Ca 3 TaGa 3 Si 2 O 14 (CTGS) piezoelectric crystal was investigated, where an external current was driven across the graphene film. Here we show for the first time that the application of the DC field leads to a significant enhancement of the SAW magnitude and, as a result, to amplification of the diffraction satellites. Amplification of 33.2 dB/cm for the satellite +1, and of 13.8 dB/cm for the satellite +2, at 471 MHz has been observed where the external DC voltage of +10V was applied. Amplification of SAW occurs above a DC field much smaller than that of a system using bulk semiconductor. Theoretical estimates are in reasonable agreement with our measurements and analysis of experimental data for other materials.

Surface acoustic wave (SAW) propagation in a graphene film on the surface of piezoelectric crystals was studied at the BESSY II synchrotron radiation source. Talbot effect enabled the visualization of the SAW propagation on the crystal surface with the graphene film in a real time mode, and high-resolution x-ray diffraction permitted the determination of the SAW amplitude in the graphene/piezoelectric crystal system. The influence of the SAW on the electrical properties of the graphene film was examined. It was shown that the changing of the SAW amplitude enables controlling the magnitude and direction of current in graphene film on the surface of piezoelectric crystals.

Ferroelectric LiNb1–x Ta x O3 solid solutions with various Nb/Ta ratio were grown from the melt by the Czochralski method. The exact composition of the grown crystals was determined by inductively coupled plasma atomic mass spectrometry. The dependence of the crystal composition on the composition of the initial melt was obtained and explained by a wide separation between the phase boundaries of the liquid and solid phases on the LiNbO3–LiTaO3 phase diagram. Using high-resolution X-ray diffraction, the parameters a and c of a crystal unit cell were determined (LiNb0.88Ta0.12O3: a = 5.1574 Å and c = 13.8498 Å). Further, the Curie temperature T C of the crystals was measured using the differential scanning calorimetry technique. T C was found to depend on the composition of the crystals that allowed conditions for the monodomainization of the grown crystals to be defined (LiNb0.88Ta0.12O3: T C = 1102°C; LiNb0.33Ta0.67O3: T C = 794°C). Finally, the velocity of surface acoustic waves was determined by scanning electron microscopy and X-ray diffraction techniques (YZ-cut of a LiNb0.88Ta0.12O3 crystal: V = 3440 m s−1).

Domain gratings with different periods were formed on −Z surfaces of lithium niobate using direct electron beam writing (DEBW) at an accelerating voltage of 15 kV. Features of the gratings obtained were compared to computer simulation results of spatial distribution of an electric field for various schemes of e-beam charges disposed near the sample surface. The Monte Carlo method was used to calculate the injection charge distribution. The electrical potential distribution in irradiated samples was determined by the numerical solution of the Poisson equation. The electric field created by the injected charges was calculated both near the surface and by the depth of the irradiated samples. Peculiarities of the field distribution have been found, in which the formation of regular domain gratings is broken due to the proximity of the injected charges. Based on computer simulations and the experimental results of DEBW (at 15 kV), the search for irradiation schemes was carried out to reduce the limitations in grating periods by decreasing the accelerating voltage of electrons up to 10 kV.

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The possibility of creating resonant ultraviolet (UV) sensors based on the structure of ZnO nanorods/La3Ga5SiO14 microbalance (LCM) has been investigated. The principle of sensor operation is based on the desorption of oxygen from the surface of ZnO nanorods upon irradiation with UV light and an increase in the concentration of charge carriers that leads to an increase in the capacitance of the structure of ZnO nanorods/LCM. It has been shown that UV radiation intensity affects the resonance oscillation frequency of the LCM sensor. After the end of irradiation, the reverse process of oxygen adsorption on the surface of ZnO nanorods occurs, and the resonance frequency of the sensor oscillations returns to the initial value.

X-ray Bragg diffraction in sagittal geometry on a Y-cut langasite crystal (La3Ga5SiO14) modulated by Λ = 3 µm Rayleigh surface acoustic waves was studied at the BESSY II synchrotron radiation facility. Owing to the crystal lattice modulation by the surface acoustic wave diffraction, satellites appear. Their intensity and angular separation depend on the amplitude and wavelength of the ultrasonic superlattice. Experimental results are compared with the corresponding theoretical model that exploits the kinematical diffraction theory. This experiment shows that the propagation of the surface acoustic waves creates a dynamical diffraction grating on the crystal surface, and this can be used for space–time modulation of an X-ray beam.