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.

This work presents a detailed comparison of our computer simulation study with our own experiment on coatings of aluminium wires for high-voltage lines and characterization of coatings. Computer modelling, using finite element method (FEM), has shown a significant dependence of a local electric field enhancement factor ( β -factor) on the surface hydrophilicity (wettability). Modelling explained that the β -factor from a micro-tip on a high-voltage line can be decreased with dependence from contact angles. It has been shown that highly porous and hygroscopic properties of the modified surface reduce the contact angle of water droplets on the wire and the β -factor from the rough surface due to the dielectric shielding. Newly engineered surfaces allow for control of the contact angle of a water droplet on the wire and also reduce the β -factor, in comparison with an uncoated surface.

Aluminum wire of AS300/39 grade with coatings synthesized by micro-arc oxidation in an electrolyte containing additives of graphene oxide and carbon nanotubes was tested under conditions of...

The spontaneous self-organization of a porous surface mosaic structure in the form of islands of oxidized por-Si nanocrystallites separated by silicon ledges has been observed during prolonged anodic etching of p-Si (100) in electrolytes with an internal current source. The por-Si mosaic structure is spontaneously formed as a result of relaxation of an elastically strained layer of the porous surface. The self-organization of the mosaic structure of the por-Si surface, island sizes, and the period of their arrangement are controlled by a number of factors arising in the complex heterophase system electrolyte/por-Si/c-Si/during etching, i.e., the spatio-temporal distribution of point defects of interstitials I _Si and vacancies V _Si in the c-Si surface region, the formation of capillary fluctuation forces at the electrolyte/por-Si/c-Si/interface, the elastic deformation forces induced by the lattice parameter mismatch between the oxidized por-Si nanocrystallites and the c-Si matrix. The conditions responsible for the manifestation of these forces depend on the self-consistent parameters of etching of the complex heterophase electrochemical system electrolyte/por-Si/c-Si/with an internal current source, including the electrode characteristics and cell parameters.

The results of electron microscopy investigation of morphology of porous silicon (PS) received under long anodic etching by using internal current source in electrolytes such as HF:H₂O₂:H₂C₅OH and HF:H₂O₂ are presented. Mosaic structure of nanoporous silicon is observed as the islands separated by silicon ledges. It was shown that these islands are presented as assemble of oxidized nanocrystallites and silicon ledges. The results of elemental analysis of islands of oxidized nanocrystallites and silicon ledges are presented.