VOL 97, No. 10 (2024)

Phosphate glasses heavily doped with Nd3+ ions are critical components in developing efficient near-infrared laser systems. This study investigates the luminescence sensitization of Nd3+ ions in BaO-P2O5 glass using silver nanoaggregates. The research demonstrates that thermally stimulated formation of Agmn+ molecular clusters multiplies the photoluminescence of Nd3+ ions in 15 folds, whereas the formation of plasmonic nanoparticles leads to a less increase. These findings open new avenues for manipulating the properties of phosphate glasses and enhancing the efficiency of laser systems.

A method of analytical calculation of the thermal conductivity coefficient of glass is proposed, which allows, by taking into account the physical essence of the process of radiation-conductive heat transfer in translucent media, to increase the reliability of calculations for different thicknesses of products, taking into account their temperature, and simplify the analysis of temperature conditions during glass cooking and operation of products made from it.

The paper presents the results of experimental modeling of glass-like carbon synthesis from high pressure supercritical fluid in the C–O–H system at temperature 800 °C and pressure 500…1000 atm. A full characterization of the carbon material is described on the basis numerous methods, such as CHNS-O analysis, scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, X-ray and electron diffraction, infrared and multiwave Raman spectroscopy. According to the features complex and comparison with industrial glassy carbon, the produced carbon material is classified as a glass-like substance. The results of the experimental synthesis demonstrate possible different formation mechanisms and, as a result, the polygenesis of glass-like state of carbon. The resulting material, due to a radically different method of synthesis (by polycondensation), can potentially have special surface and bulk properties.

The results of the synthesis of complex paraniobate of the composition YErYbNbO7 using various methods are presented. The chemical composition of the final synthesis products is determined. The features of the thermal behavior of the precursors are revealed. The crystallographic parameters of single-phase samples are calculated and the sizes of crystallites are determined.

In this study, we investigated how the composition and ratio of sintering additives MgO and CaO influence the optical properties of ceramic materials YAG:Cr3+ and YAG:Cr4+. All samples exhibited high transparency at 1100 nm (greater than 80 %). However, around ~340 nm, increased concentrations of Ca2+ or Mg2+ ions resulted in decreased light transmission coefficients for the samples. Following annealing in air, the most pronounced absorption in the 750…1100 nm range was observed in samples with higher amounts of sintering additives. As the fraction of Ca/Mg increased, so did the absorption of Cr4+ cations. Among the compositions studied, an optimal CaO content of 0.12 wt. % was identified; beyond this level, additional absorption due to microdefect formation was noted. Scanning electron microscopy data revealed a granular structure for the ceramic samples, with grain sizes ranging from 1 to 10 ?m, showing no significant variations in microstructure based on the type or quantity of sintering additives.

Cu-series green glaze was prepared using raw materials such as kaolin, feldspar, calcite, talc, limestone, quartz, and copper oxide. This study investigated the effects of formulation composition and preparation process on the glaze surface of the green glaze using both single-factor method and orthogonal experimental design. The single-factor method involved systematically varying one factor at a time, such as the proportions of raw materials, firing temperature, and firing time, to observe their individual effects on the green glaze surface. On the other hand, the orthogonal experimental design considered multiple factors simultaneously and analyzed their relative importance on the glaze effect. By employing these methods, the study aimed to optimize the formulation composition and preparation process of the copper-based green glaze to achieve the desired glaze surface effect. To improve the efficiency and quality of glazes in industrial production applications.

The structure of ZrO2–Sc2O3 powders in the composition range from 1 to 15 mol. % Sc2O3 with the addition of 0.1 mol. % Eu2O3 as a spectroscopic probe, obtained by the coprecipitation method and heat-treated at temperatures from 500 to 1200 °C, was studied. The crystal structure was identified by the X-ray diffraction method and Raman spectroscopy. The local structure was estimated by the spectral and luminescent properties of the Eu3+ ion in the powder preparations.