Inorganic Materials: Applied Research最新文献

Compounds of antimony(III, V) were obtained: {[2,6-(ОMe)₂C₆H₃)₃]EtSb}I, [(2,6-OMe)₂C₆H₃]₃SbO, [Sb(μ₂-O)Cl(DMSO-О)]_n, [(2,6-OMe)₂C₆H₃]₃Sb(N₃)₂, (C₆H₅)₃SbBr₂, [(C₆H₅)₃Sb(NCO)]₂O⋅C₄H₈O₂, being by potential ferroelectrics. Temperature dependences of the permittivity of the compound were studied. According to dielectric measurements, it was established that for the compound [(C₆H₅)₃Sb(NCO)]₂O⋅C₄H₈O₂ a phase transition is observed at a temperature of 164°C. The presence of hysteresis on the temperature dependence of ε' indicates a first-order phase transition.

ZnS:Cu, Br (0.005–0.01, 0.8 wt %) radioluminescent materials were synthesized for the first time from solid charge mixtures using a microwave sintering. The temperature range of zinc sulfide matrix recrystallization at microwave synthesis was determined in a range of 600–650°C. The microstructure and phase composition of the synthesized luminescent materials were studied; it was shown that at 650°C, a complete phase transformation of the ZnS matrix into a high-temperature wurtzite modification occurs. The spectral and brightness characteristics of tritium radioluminescence were obtained and compared with samples synthesized using a traditional solid-phase method.

The structural and hysteresis properties of epitaxial MgO(100)/⁵⁷Fe(50 nm)/Cr(2 nm) films grown by molecular beam epitaxy (MBE) were investigated. Changes in structural properties during annealing in the temperature range of 200–300°C were studied using X-ray diffraction, Raman spectroscopy, atomic force microscopy and Mössbauer spectroscopy. It was shown that at temperatures above 250°C, oxygen diffusion through the protective Cr layer occurs, leading to the formation of antiferromagnetic α-Fe₂O₃ oxide. The temperature dependences of hysteresis properties during annealing were determined. At an annealing temperature of 280°C, the coercive force reaches a maximum value of 190 Oe. The absence of exchange bias, evidenced by zero shift in the hysteresis loops, suggests the dominant role of low magnetic anisotropy of α-Fe₂O₃ and interface disorder in these oxidized heterostructures.

The paper presents studies on modification of a polyurethane membrane in a low-energy ion flow in an argon environment. The studies have shown the possibility of changing the surface structure and physical and mechanical properties of the polyurethane membrane.

The study investigates physical mechanisms underlying plasma-assisted modification of capillary-porous materials, such as natural leather and fur, using low-energy ion flows generated in a capacitively coupled RF discharge at intermediate pressure (13.3–133 Pa). The proposed model demonstrates that material modification occurs through three interconnected processes: interaction with low-energy ions (up to 100 eV) from the positive charge layer, ion recombination energy release, and bulk treatment effects mediated by non-self-sustained discharge inside the material’s porous structure.

Theoretical calculations on the nonlinear optical properties of nematic liquid crystals are presented, investigated using the polarization-optical method (POM) and differential scanning calorimetry (DSC). It was shown that, depending on the time scale, different processes induce a nonlinear optical response. It was discovered that, on the millisecond time scale, the source of the nonlinear optical response is thermal and depends, among other factors, on the main parameters that exclude mesophases, such as temperature and relative composition. It was suggested that the coupling of bonds and conformational changes play a significant role in these processes. It was established that, in the studied liquid crystals, the nonlinear response on the millisecond time scale has a thermal origin and depends on the specific mesophase, the relative concentration of components, and temperature. The deviation from the phenomenological Beer-Lambert law suggests the existence of interaction between the micelles and magnetic particles, the nature of which is still not fully understood.

The interaction between uranium dioxide granules and hydrogen fluoride has been studied, including: thermodynamic evaluation was given, the reaction mechanism was proposed using the model of reactive “shrinking core,” laboratory experiments on fluorination of uranium dioxide granules with hydrogen fluoride gas were performed.

Metal and metal oxide nanopowders synthesized via cryochemical technologies are distinguished by their absence of toxic reagents, solvents, and stabilizers, rendering them well-suited for biomedical applications. In this article, the cryochemical approach—cryogenic precipitation of silver and zinc as carbonates and their subsequent thermal decomposition—is used to produce highly dispersed silver and zinc oxide powders. The size of the obtained nanoparticles is 1–7 nm for silver and 7–17 nm for zinc oxide. Obtained nanoparticles and their precursors were characterized by X-ray diffraction, FTIR-, UV-spectroscopy, and TEM methods.

studies have been conducted on changes in fatigue and long-term strength of samples made of materials ВТ-1, ВТ-3, ВТ-6, ВТ-8, ВТ-9, 20Х13, 40Х13, 12Х18Н9Т, 08Х18, steel 45, steel 30.

The dependence of the potential barrier height at the metal/polymer interface on the number of elastic deformation cycles of the metal was studied. The objects of the study were structural steel and a wide-bandgap dielectric polymer from the poly(arylene phthalide) class, poly(diphenylene phthalide). It was found that the dependence has a complex form with a periodic component. With a relatively small number of deformation cycles, a sharp decrease in the barrier height is observed, and then small fluctuations. The barrier height increases as the number of cycles approaches the threshold value at which the sample fracture occurs. Immediately before the fracture, a sharp decrease in the potential barrier height is observed. In this case, the polymer film can transition to a state with high conductivity. That is, electronic switching occurs. The absolute change in the barrier height was ∼250 meV, and the change in resistance from 2 to 6 orders of magnitude, which can be used to develop a method for non-destructive testing of the state of metals.