Development of Radio-Absorbing Ceramics Based on SrO–BaO–TiO2–SiO2 System Compositions

The paper investigates the features of the formation of radio-absorbing ceramics based on barium and strontium titanates for use in masking systems for special objects. The concept of creating heterophase materials with a controlled dielectric constant, which is provided by the controlled synthesis of target phases, is implemented. The physicochemical analysis of the SrO–BaO–TiO2–SiO2 system is carried out, a model state diagram of its subsolidus part is constructed. The phase relationships in the BaTiO3–SrTiO3–SiO2 section are investigated, and the phase triangle SrTiSiO5–BaTiO3–SrTiO3 is determined as the most technological region of compositions for the synthesis of target phases. Using two-stage solid-state sintering (1250 – 1350 °C – first firing, 1380 °C – second firing), materials were obtained, for which the phase composition, dielectric permittivity and electromagnetic properties were studied. The materials are characterized by a wide range of variation in dielectric permittivity (21.0-71.5), which is due to their phase composition. The formation of SrTiO3, solid solutions of Ba0.5Sr0.5TiO3 і Ba0.9Sr0.1TiO3 and in various combinations was experimentally con-firmed, as well as the possibility of regulating their ratios in the final product by changing the composition of the initial compositions and the temperature of the firing. The attenuation and reflection coefficients of the electromagnetic wave, as well as the wave resistance of the materials at a frequency of 0.1GHz, were deter-mined and it was established that they belong to ceramics with a medium and high level of radio wave ab-sorption. The feasibility of using the developed materials as functional and matching layers in gradient radio-absorbing compositions intended to protect special objects from microwave radiation is shown.