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The transfer of droplets through a microgap under a thin barrier in the direction opposite to the motion of the surface acoustic waves (SAWs) acting on them has been discovered. Initially, the droplets are in contact with the barrier on the side opposite the SAW source. Under the SAW action, the transfer of a significant portion of the droplet volume through the microgap to the opposite side of the barrier is observed. This is in contrast to the behavior of droplets not in contact with the barrier. These droplets move in the direction of SAW motion. Experiments were performed to determine the effects of droplet size, SAW source power, and barrier wettability on the intensity of anomalous transfer. In addition, a computer simulation of a system simpler than the original was performed to identify the processes responsible for droplet growth on the side of the barrier facing the SAW source. Based on the analysis of the experimental and computational results, a model is proposed to explain the discovered phenomenon. The model assumes that the initial stage of anomalous transfer is due to atomization–coalescence, and the subsequent, more intense stage is due to the specificity of the streams circulating in the growing droplets. The article also shows that in a system of two parallel barriers, anomalous transfer allows either droplet division or droplet division and mixing. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

An investigation is performed of planar memristive structures to validate the choice of their basic materials, study their functional properties, and determine and develop the structure the resistive switching mechanism. Mesoscopic heterostructures based on epitaxial 〈001〉 oriented films of high-temperature superconductor YBa2Cu3O7 − δ and doped manganite La1 − xSrxMnO3 − δ, are obtained, and the properties of the percolation channels of structures based on these compounds are studied. Self-adaptive electroforming effects in microcontact heterostructures based on epitaxial manganite films are studied. Numerical calculations using the critical electric field model show there is self-electroformation in strong electric fields, and a gap structure that provides resistive switching reproducibility forms in the zone of contact. [ABSTRACT FROM AUTHOR]

We have been studying the dynamic effects of bipolar resistive switching (BERS) in memristive planar heterostructures based on c-oriented epitaxial films of the high-temperature superconductor YBa2Cu3O7 (YBCO). We have been observing the suppression of the memristive properties of the structures under sinusoidal and pulse loads and the nucleation and the evolution of the regions of current density and electric field in the structures under study. We found that the limiting frequencies of a sinusoidal type load for observing the switching effect are frequencies of about 104 Hz. It has been shown that the percolation channel is formed by the appearance of electric field domains in which the electric field threshold is reached. The switchings are controlled by two processes, with time t < ms and a longer time of the order of a few seconds. Possible physical models of the observed phenomena are being discussed. [ABSTRACT FROM AUTHOR]