The July 2025 issue of Glass and Ceramics magazine has been published

Dear colleagues!

Victor Osipov, President of the Association "StekloSouz" of Russia, is a member of the editorial board of the Glass and Ceramics magazine.

We inform you that the 7th issue of the monthly scientific and technical magazine Glass and Ceramics for 2025 has been published.

Contents of the July issue:

- SPECTROSCOPIC PROPERTIES OF ZINC PHOSPHATE GLASSES DOPED WITH Er3+ IONS

The spectral and luminescent properties of zinc phosphate glasses in the ZnO–P2O5 (PZ) system doped with 0.25…1.00 mol. % Er2O3 were studied. It was shown that an increase in the Er2O3 content in the synthesized glasses leads to an increase in the intensity of the luminescence band with a maximum at a wavelength of ~1537 nm. The values of the phenomenological parameters of the Judd–Ofelt intensity ?t (t = 2, 4, 6) were estimated, based on which the probabilities of radiative transitions, branching coefficients, stimulated emission cross sections, and radiative lifetimes of the excited state were calculated. The results demonstrate the promise of using the material under study as a light-emitting medium in the near IR range.

- DIELECTRIC PROPERTIES OF LEAD ZIRCONATE CERAMICS OBTAINED FROM PbO AND ZrO2 NANOPOWDERS

The paper presents the results of the study of the dielectric properties and harmonic coefficient of lead zirconate ceramics synthesized at different sintering temperatures from the initial PbO and ZrO? powders with particle sizes of 500 and 20 nm, respectively. It has been established that the use of nanodispersed powders allows for a decrease in the sintering temperature compared to traditional technical ceramics made from 1 μm particles. The maximum value of the dielectric constant was recorded for ceramics sintered at a temperature of 1100 °C. With an increase in the sintering temperature above 1200 °C, a decrease in the dielectric constant is observed, however, upon cooling in the range of 226…208 °C, a ferroelectric phase is formed.

- LOW-TEMPERATURE CERAMICS BASED ON WOLLASTONITE AND PEROVSKITE MODIFIED WITH AL2O3–CUO–LI2CO3 ADDITIVE FOR LTCC TECHNOLOGY

Ceramics based on wollastonite ?-CaSiO3 with additives of perovskite and sintering aluminum-copper-lithium additive were obtained. The effect of the sintering additive on the ceramic and dielectric properties in the CaSiO3/Al2O3–CuO–Li2CO3 and CaSiO3/CaTiO3–Al2O3–CuO–Li2CO3 systems is described. Thermal conductivity ? of the obtained samples is in the range of 0.43…0.65 W/(m?K), which is typical for wollastonite ceramics. The permittivity was ?r = 4.9…8.0, the dielectric loss tangent was tg? = (15.3…17.9)?10–3 at a frequency of f = 1 MHz, and the average density was ?cp = 2.44…2.63 g/cm3. The samples were sintered at temperatures of 875…950 ?C. The properties of the resulting ceramics, combined with low thermal conductivity ?, meet the requirements for heat-resistant ceramic housings and boards for microelectronics using LTCC technology.

- ELECTRON BEAM SINTERING OF ZIRCONIUM DIOXIDE-BASED CERAMICS WITH VARIOUS YTTRIUM OXIDE CONTENTS

The article presents the results of a study of the effect of various fractions of the stabilizing impurity yttrium oxide Y2O3 on the microstructure, phase composition and mechanical properties of zirconium dioxide-based ceramics ZrO2 obtained by electron beam sintering in the forevacuum pressure range. Ceramics with a mass content of Y2O3 from 1.8 to 31.5% were studied. It was shown that an increase in the proportion of Y2O3 in ZrO2-based ceramics leads to a decrease in the density of the sintered ceramics, but at the same time contributes to the stabilization of the tetragonal phase of ZrO2. This has a positive effect on its strength characteristics, taking into account the absence of pressure during the sintering process. It was established that the optimal Y2O3 content for achieving high microhardness (up to 5.64 GPa) is 15%.

- CORUNDUM CERAMICS BASED ON RUSSIAN RAW MATERIALS WITH LOW SINTERING TEMPERATURE

The physical and mechanical properties of corundum ceramics based on domestic alumina grade G-00 were studied. The best mechanical strength indicators were obtained for ceramics fired at a temperature of 1450 ?C, containing 5 wt. % yttrium oxide and 5 wt. % eutectic additive MnO–TiO2. The prospects for import substitution of alumina are shown.

- PHASE FORMATION OF NEW PYROCHLORINE-LIKE OXIDE CERAMICS OF THE COMPOSITION BI2.7ZN0.46NI0.70SB2O10 + ?

The process of phase formation of new antimony pyrochlore (sp. gr. Fd-3m) of the composition Bi2.7Zn0.46Ni0.70Sb2O10 + ? during solid-phase synthesis from oxide precursors was studied. The process of solid-phase synthesis of antimony pyrochlore of the composition Bi2.7Zn0.46Ni0.70Sb2O10 + ? is a complex multi-stage process. It is shown that active interaction of oxide precursors occurs at a temperature above 600 °C, resulting in the formation of the primary intermediate phase Bi3SbO7. Oxide precursors, including bismuth (III) and antimony (III, V) oxides, are fixed in the sample in an individual state up to a temperature of 750 °C, above which a cubic phase Bi3M2/3Sb7/3O11 (sp. gr. Pn-3), stable up to 900 °C, is formed. The pyrochlore phase in the sample appears at 650 °C, a significant increase in the proportion of pyrochlore occurs at a temperature of 850 °C and above. Phase-pure pyrochlore is formed at 950…1050 °C. At a temperature of 1050 °C, sintering of fine-grained ceramics occurs, a low-porosity microstructure is formed due to the fusion of small grains with the formation of coarse crystallites with a longitudinal size of 2…4 μm. The unit cell parameter of pyrochlore in the range of 650…1050 ?C changes non-monotonically, at 800 ?C the minimum value of 10.464 ? is recorded, the cell constant of phase-pure pyrochlore of the composition Bi2.7Zn0.46Ni0.70Sb2O10 + ? is 10.474 ?.

- PROSPECTS OF USING CLAY RAW MATERIALS FROM THE STOLINSKIE KHUTORA DEPOSIT FOR THE PRODUCTION OF CONSTRUCTION CERAMICS

The studies of the technological properties of clay raw materials from the Stolinskie Khutor deposit (Vidibor site, Brest region) were carried out, which made it possible to classify the specified natural fine-grained material according to GOST 9169–2021. It has been established that the clay is refractory, highly plastic, semi-acidic or acidic (depending on the depth of occurrence) with a high or medium content of coloring oxides, coarsely dispersed, non-caking in the firing temperature range of 900...1200?. The phase composition of the clay material, as well as the processes occurring during its heat treatment, have been studied. It has been determined that the clay in question can be used in the production of ordinary brick and stone, clinker material, as well as ceramic tiles for flooring. Samples of building ceramics obtained in laboratory conditions using clay from the Stolinskiye Khutor deposit have the necessary set of physical, chemical and operational characteristics.

- HEMATITE ORE OF THE KYZYLTASH DEPOSIT – A PROMISING RAW MATERIAL FOR CERAMIC PIGMENT

The results of the study of the chemical and mineralogical composition of the hematite mineral of the Kyzyltash deposit before and after firing are presented, the methods of its enrichment are selected. Red and brown pigments are synthesized, the results of X-ray phase and electron microscopic analyses are analyzed. The coloring properties of the obtained red and brown pigments are studied. It is established that hematite of the Kyzyltash deposit can be used as a raw material component at manufacturing enterprises of the building materials industry of Uzbekistan for the preparation of ceramic glazes of coloring pigments.