The subject matter of the study is the dielectric and photodielectric properties of AIIBVI crystals of composition ZnSe and Cd1-хZnхTe, which are grown from the melt, and the structural defects and internal elastic fields associated with these properties. The goal of the article is to study the patterns of influence of surface machining by grinding, polishing, and local loading on the defective structure in the deformation region, and thus on the dielectric and photodielectric properties of AIIBVI crystals of this composition, which is important given the use of these crystals in aerospace engineering. The tasks to be solved are: to investigate the regularities of the influence of grinding, polishing, and local deformation of the chipped surface of ZnSe and Cd1-хZnхTe samples on their defective structure, dielectric and photodielectric properties, including irreversible changes in properties. The problems were solved by the following methods: dielectric and photodielectric properties of crystals were investigated by the capacitive method; scanning photodielectric spectroscopy was used to measure the photoionization energies of localized states of charge carriers in crystals; the distribution of residual elastic stresses in the samples was studied by the polarization-optical method. The following results were obtained. Grinding and polishing cause the transformation of own and impurity maxima of the spectral dependences of the dielectric parameters of AIIBVI crystals, has a characteristic effect on the coordinate dependences of the dielectric parameters of crystals Cd1-хZnхTe. This is due to the transformation of localized states of carriers, which is confirmed by the study of ZnSe crystals. Concentrated deformation of Cd1-хZnхTe crystals significantly affects their dielectric properties, in particular, causes relaxation of dielectric parameters. Conclusions. Mechanical surface treatment of AIIBVI crystals by grinding and polishing, as well as local mechanical loading of Cd1-хZnхTe samples significantly affect their dielectric and photodielectric properties, which is associated with the formation of a system of defects and internal elastic fields in the deformation regions. An explanation of the observed effects is given.

It's shown the necessity to use functional coatings in engineering, which can be formed in many layers and contain a number of components what based on the analysis of literature data about ways to ensure the required resource of machine parts and mechanisms. Existing technologies and the corresponding equipment require the prefabricating of the alloys which the coatings are formed. This significantly limits the control of the coatings' composition. It's shown the advantage of ion-plasma technologies developed at National Aerospace University "Kharkiv Aviation Institute" over the existing technologies. In particular, due to the spraying of a large number of cathodes-targets, these technologies allow the formation of multicomponent coatings of almost any composition. When implementing ion-plasma technology for the formation of coatings, a decisive role plays the generator of the flow of particles of the coating material. It has been proposed to supply voltage to each generator element through a chain of resistors, the total resistance of which is regulated by the control system of the corresponding program to improve the power supply system of such a generator. Such an approach to the improvement of the power supply system of the technological generator of the coating material is implemented in the developed laboratory experimental-industrial process plant for the formation of a model coating of tungsten carbide. It was considered two possible schemes for creating resistive chains with regulated resistance. It was selected the scheme, which consists of a smaller number of elements. The important role of any resistive chain in the operation of the technological generator control system has been determined. It was proposed the optimal choice of the nominal values of the resistors included in the chain. The optimal choice of the nominal values of the resistors included in the chain has been proposed. The conducted analysis of experimental data carried out by the authors suggests that each such chain should have individual features, in particular, the boundaries and the step of resistance, the maximum power of heat losses. These and other parameters are usually determined experimentally.

The subject matter of study in the article is the optical, dielectric and photodielectric properties of ZnSe crystals containing macroscopic structural inhomogeneities. The goal of this work is to study large-scale inhomogeneities in ZnSe crystals, which is important for determining the suitability of their application in technology. The tasks to be solved are: in a crystalline ZnSe ingot of cylindrical shape in the optical range at perpendicular to the light flux orientation of the sample axis to detect macroscopic inhomogeneities and establish their relationship with the features of the dielectric properties of the local regions of the ZnSe ingot; to investigate the influence of nonmonochromatic light flux on the distribution of dielectric parameters along the axis of the ZnSe ingot containing areas of macroscopic inhomogeneities. The problems were solved by the following methods: the homogeneity of the zinc selenide ingot was studied by the polarization-optical photoelasticity method; the photometry method was used to study the intensity distribution of the light scattered by the sample perpendicular to its axis; the dielectric properties of a crystalline ZnSe ingot were investigated by the capacitive method. The following results were obtained. In ZnSe crystals regions of three types were found: isotropic, weakly anisotropic, and anisotropic. Sharp changes in the intensity of scattered light are observed in the region of large-scale optical inhomogeneity, and light scattering in this region occurs anisotropically. The angular dependences of C and tgδ at an electric field frequency of 1 kHz are obtained for the region of large-scale optical anisotropy. The changes in dielectric parameters under the action of nonmonochromatic light along the sample axis are measured. Conclusions. It was found that ZnSe crystals are characterized by large-scale inhomogeneities of the investigated properties. A close relationship is noted between the optical and electrophysical properties, which is probably due to the mutual influence of two-dimensional and point defects on the formation of a defect structure during the growth and further cooling of the crystal.

The consideration of the features of constructing the power supply system of a pilot industrial-technological installation for applying multicomponent coatings by the ion-plasma method is continued. The main attention is paid to the practical aspects of developing controlled resistive circuits connected to various elements of the power supply circuit of a technological plasma generator. It is noted that the control of the operation mode of the technological installation is provided by changing the resistance of these chains by the corresponding automated system. A mathematical expression is proposed in the form of a polynomial for the resistance of chains, which meets the requirements for a research installation and the condition for minimizing the number of resistors in a separate chain. The structure of the chain is considered as a combination of the required number of cells. Each of them differs from the others not only in the connection scheme of the resistors but also in their resistance. An algorithm is proposed for determining the nominal resistance, heat loss power, the number of resistors and the circuitry for their connection. For example, a diagram and the main technical characteristics of a chain connected to a group of target cathodes from tungsten are given. Such cathodes are used in the formation of nanostructured and multifunctional coatings of tungsten carbide on the surface of metal parts. Particular attention is paid to the control elements in the individual cells of the technological plasma generator. The analysis of requirements for control elements such as semiconductor switches and electromagnetic relays is carried out. It is noted that these requirements are met by conventional (not high-voltage) electromagnetic relays of domestic production, provided that their contacts are connected in series with each other. Attention is drawn to the need to prevent the formation of an electric arc when the relay contacts open, can be achieved by including a resistor and a capacitor in series with the control element. It is also important to use means of forced air cooling of the resistive chain block.