Steklo i Keramika (Glass and Ceramics). Monthly scientific, technical and industrial journal

 

ISSN 0131-9582 (Online)

VOL 96, No. 3 (2023)

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  • MIDDLE RANGE ORDER IN GLASSES OF La2O3–Nb2O5–B2O3 AND BaO–Nb2O5–P2O5 SYSTEMS ACCORDING TO X-RAY TOTAL SCATTERING

    • Pages: 3-11
    • Views: 149
    We have obtained the X-ray total scattering patterns at wavelength 0.20735 ? and corresponding to them radial distribution functions (RDF) of electron density for glasses in the La2O3–Nb2O5–B2O3 and BaO–Nb2O5–P2O5 systems. The RDF demonstrate separate peaks at distances below ~1 nm which points on the middle range ordering in the considered glasses. The consideration of RDF for BaO–Nb2O5–P2O5 glasses system with high concentration of BaO show that the middle range order is caused by the polyhedra chains of ideal BaO crystal, and these chains does not belong to any low-index crystal plane. For La2O3–Nb2O5–B2O3 glasses system the polyhedra chains are observed which resemble those in the LaB3O6 crystal, with polyhedra bound through borate groups. For all considered glasses the niobium polyhedra does not form extended chains.
  • THE ROLE OF IRON OXIDES IN THE PRODUCTION OF FLOAT GLASS

    • Pages: 12-16
    • Views: 138
    A statistical analysis of the relationship of the redox ratio of the produced float glass with the technological mode of cooking, the charge content and the chemical composition of the glass was carried out. The influence of the redox ratio on the technical and economic performance of the bath furnace and the quality of the glass produced is shown.
  • INVESTIGATION OF THE STRUCTURE AND INFLUENCE OF ION EXCHANGE ON THE MICROHARDNESS OF LOW-ALKALI TRANSPARENT GANITE GLASS-CERAMICS

    • Pages: 17-25
    • Views: 149
    Transparent glass-ceramics are attracting more and more attention as a material for protecting the screens of electronic devices. The paper considers the possibility of carrying out ion-exchange of transparent gahnite glass-ceramics containing a small Na2O content. The structure and properties of glass-ceramics before and after ion-exchange were studied by x-ray diffraction analysis, transmission electron microscopy, Raman spectroscopy, laser-induced breakdown spectroscopy, and Vickers hardness determination. It is shown that, under certain conditions, ion-strengthening of glass ceramics with a low content of alkali ions can lead to an increase in microhardness values.
  • ELECTRICAL CHARACTERISTICS OF BISMUTH-CONTAINING CERIUM OXIDE

    • Pages: 26-32
    • Views: 133
    Ceramics Ce0.9Bi0.1O2 – ? was obtained by solid-phase synthesis. It is shown that the obtained samples have a cubic fluorite structure with the space symmetry group Fm3m. The electrical properties of the Ce0.9Bi0.1O2 – ? solid solution were studied by ac impedance spectrometry. It has been established that the activation energy of electrical conductivity has two sections 0.51 eV (400 – 680 ?С) and 1.6 eV (680 – 800 ?С), the activation energy of the dielectric relaxation process was 0.88 eV.
  • SYNTHESIS AND CHARACTERIZATION OF NEW PEROVSKITE-TYPE PbNaKNb2FeO9.5 CERAMIC

    • Pages: 33-38
    • Views: 138
    Lead-containing perovskite of complex composition PbNaKNb2FeO9.5 (sp. gr. Pnma, a = 5.654 ± 0.003 ?, b = 7.977 ± 0.001 ?, c = 5.646 ± 0.003 ?) was synthesized for the first time by the solid-phase reaction method. The sample is characterized by a non-porous microstructure formed by randomly oriented cubic crystallites. The band gap (?2.10 eV) of a complex perovskite for a direct allowed electronic transition was calculated from the data of the diffuse reflectance spectrum. The permittivity of the sample at room temperature and a frequency of 106 Hz reaches 1365, and the dielectric loss tangent is 0.1.
  • ANTIBACTERIAL PROPERTIES OF BOROSILICATE ENAMEL WITH NANOSCALE ZINC OXIDE PARTICLES

    • Pages: 39-47
    • Views: 148
    Glass-enamel coatings have been modified with nanosized particles, which expands the scope of their application and is a promising direction. It has been established that the introduction of nanosized zinc oxide in the amount of 0.5 wt. % into the composition of the enamel of the Na2O–B2O3–TiO2–SiO2 system imparts antibacterial properties to the coating against gram-positive and gram-negative bacteria. The meaning of the index of antibacterial activity of the surface of the enamel increases on average five times more in relation to Escherichia coli (E. coli) and six times more in relation to Staphylococcus aureus (St. aureus) compared with a control sample that does not contain zinc oxide.
  • TECHNOLOGIES FOR OBTAINING FLEXIBLE THERMAL INSULATION MATERIAL

    Autors: Istomin A. V.
    • Pages: 48-56
    • Views: 147
    The main directions of application of flexible heat insulating materials and traditional technologies for producing non-woven materials are considered. Various ways of fastening fibers are analyzed, such as: chemical; thermal; mechanical, which in turn includes the following options: needle-punched, knitting-stitching, hydro-jet method used in the production of flexible fibrous thermal insulation. A number of patents are presented that develop methods for obtaining nonwoven materials.