The formation of arrays of Ag and Au nanoparticles from the vapor deposition phase on an unheated thin-film amorphous carbon substrate has been systematically investigated using transmission electron microscopy. It has been found that there is a significant dependence of the size of particles and the density of their location on the surface on the amount of evaporated silver or gold. In particular, for a gold sample weighing ∼2 mg, the predominant diameter of clusters is ∼9 nm at a surface distribution density of ∼10000 μm⁻², whereas during evaporation of a larger sample weighing ∼11 mg, the predominant diameter of clusters is ∼35 nm at a surface distribution density of ∼200 μm⁻². A phenomenological description of the formation of an array of nanoparticles through thermal evaporation and condensation under vacuum onto an unheated surface has been presented. The specific features of the process have been considered. It has been concluded that the nucleation of a silver or gold particle on the surface gives rise to a flow of vaporous silver or gold, which is directed to this particle and, thus, maintains it in a hot state and determines its growth.

The photocatalytic activity of TiO₂ depends on numerous factors, such as the chemical potential of electrons, charge transport properties, band-gap energy, and concentration of surface-active sites. A lot of research has been dedicated to determining the properties that have the most significant influence on the photocatalytic activity of semiconductors. Here, we demonstrated that the activity of TiO₂ in the gas-phase reduction of CO₂ is governed mainly by the desorption rate of the reaction intermediates and final products. This indicates that the specific surface area of TiO₂ and binding strength of reaction intermediates and products are the main factors affecting the photocatalytic activity of TiO₂ in the investigated process. Additionally, it was shown that rutile exhibits higher photocatalytic activity than anatase/rutile mixtures mainly due to its high efficiency in the visible portion of the electromagnetic spectrum.

The decomposition of thin silver films into clusters on a SiO₂ surface during thermal heating in vacuum has been studied. The experimental histograms of distribution of clusters formed from films of different thicknesses over their diameters have been constructed. It has been found that the decomposition of the films with thickness to 10 nm leads to the formation of monoclusters having one predominant diameter in the range from 15 to 20 nm. After a longer term annealing, the array of clusters almost does not change with time, and the predominant diameter is retained. From films with thicknesses ranging from 10 to 130 nm, an array of clusters with two predominant diameters containing monoclusters (40–80 nm) and globular clusters (400 nm) is formed. It is noted that, with increasing annealing time, the array is enlarged due to the coalescence process and is gradually evaporated; in this case, the predominant cluster diameters remain the same.

A method for increasing the efficiency of using laser radiation (LR) energy for the formation of high levels of the equivalent dose rate, which is based on reducing the radiation wavelength, is...

The effect of ionizing radiation on the characteristics of silicon-germanium microwave ICs has been experimentally studied. Radiation tolerance criteria have been established and absolute tolerance...