The purpose of this work is to study the influence of the electric field strength of an electromagnetic wave with the maximum modifying effect on an epoxy basalt-filled oligomer, which is of great scientific and practical importance for the development of microwave oligomer modification technology. The optimal modes of microwave modification, under which the highest values of the mechanical properties of an epoxy basalt-filled polymer composite material are obtained, are identified: power of 400 W and an exposure time of 24 s. At the same time, the breaking stress in bending increases by 20%, the impact strength increases by 2 times, and hardness increases by 31%. A slight increase of 4.5% in heat resistance is noted compared to the composite obtained on the basis of an oligomer unmodified in the microwave electromagnetic field. The results of resistance to various aggressive environments are obtained, which show that the studied physical and mechanical characteristics of the epoxy basalt-filled material after exposure to an aggressive environment decrease by less than 14%, which corresponds to their good resistance to an aggressive environment. It is established that the effect of the microwave electromagnetic field on an epoxy basalt-filled oligomer is an effective modification method that improves physical and mechanical characteristics with a high level of temporal stability to climatic influences, with a coefficient of property retention of more than 90%.

The results from simulation of the structural and optical properties of YAG pure, doped with two ions and four ions of lanthanum, are presented in this paper to investigate the effect of dopants on a crystal. The simulation was carried out in the Quantum Espresso program. The band structure, density of states, the dielectric function, absorption, refractive index, energy loss function and reflectivity were calculated for different samples. It can be assumed that with a rise in concentration density of states, the impurity atom increases and the position of the most populated levels shifts to the right in the region of negative energies in the case of two atoms and to the left in the case of four atoms of lanthanum. We can draw conclusions about the transparency of the sample in the visible region, because the absorption spectra appear in the UV region. This transparent nature makes them perfect candidates for deep UV nonlinear optical materials. From the analysis of dielectric function, it is clear that in the case of YAG doped with two ions of lanthanum, two peaks appeared compared to the sample with one peak in pure and doped with four ions. Anisotropy is most pronounced with an increase in the degree of doping.

The article presents the results of measuring the luminescence spectra and luminescence excitation spectra for YAG:Eu with europium concentrations of 2, 6, 8, and 10%. The materials were synthesized by solid-phase synthesis. For samples with europium concentrations of 2, 8, and 10%, the diffraction patterns showed full agreement with the phases. However, the yttrium–aluminum–perovskite phase was present in the sample with a concentration of 6%, even though the samples were obtained under the same conditions. The spectra of the photoluminescence excitation and photoluminescence were recorded for all samples. The concentration dependences of the luminescence bands and luminescence excitation bands were also plotted. The bandgap and absorption spectra were simulated for the sample of YAG:Eu, doped with 2–4 ions of europium for comparison.

The article presents the results of measuring the luminescence spectra, luminescence excitation spectra and luminescence spectra under high pressures for LaAlO₃:Pr with concentration of 1%. The materials were synthesized by solid phase synthesis. Diffraction pattern is fully relates to LaAlO₃ phase. The photoluminescence spectra show the main energy transitions. The change in the position of the main bands under the hydrostatic pressure of 23, 55, 160 and 191 kBar was demonstrated. The main band at 491 nm is slightly red-shifted, while the line at 605 nm is shifted to the high-energy part of the spectrum. The intensity of all bands increases with increasing hydrostatic pressure. The dynamics of changes in the intensities of maxima and emissions from different transitions are analyzed. Studies of luminescence under high hydrostatic compression are important in observing changes in the internal structure and electronic states of materials under the influence of high pressure, studying internal processes such as recombination of electrons and holes, transitions between energy levels and the release of photons. Understanding the changes that occur under compression can help researchers develop new materials with unique properties.

The article presents the synthesis and characterization of double halide perovskites (DHPs) with the nominal composition Cs₂Ag_0.2Na_0.4In_0.6M_0.4Cl₆ (M = Si, Ti, Zr), including photoluminescence (PL), photoluminescence excitation (PLE) spectra measured over a range of temperatures and kinetics of luminescence. The materials were synthesized via a hydrothermal method. The phase purity and elemental composition of the synthesized perovskites were confirmed by X-ray diffraction (XRD), Rietveld refinement, scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS) and elemental analysis, which demonstrated that the samples showed a close match to the target stoichiometry. The PL spectra exhibit a systematic shift toward the lower-energy region with substitution from Si to Zr, correlating with the progressive increase in the ionic radii of the substituting cations. All samples display broad, asymmetric emission bands, characteristic of self-trapped excitonic (STE) states. Temperature-dependent PL measurements reveal a gradual decrease in emission intensity with increasing temperature for all samples. The maximum emission intensity is observed in the range of ~160–200 K, corresponding to optimal conditions for radiative recombination, whereas the lowest intensity is recorded at ~80–100 K, where thermal activation of radiative centers is minimal. An increase in temperature is accompanied by a red shift in the PL bands across all compositions. In the Ti-doped DHP, a pronounced blue shift at low temperatures is observed, which can be attributed to the involvement of Ti³⁺-related electronic states. An analysis of the activation energy of thermal luminescence quenching and the results of time-resolved spectroscopy revealed the activation of thermal processes in the titanium-containing sample and their rapid decay, whereas replacing titanium with silicon leads to more stable luminescence in the crystal under study. Thus, the enhanced luminescence characteristics of double halide perovskites doped with Ti, Si, and Zr highlight their potential for advanced photonic and optoelectronic applications.