| Popis: |
Two types of high-temperature materials based on ferroelectric solid solutions with a high dielectric constant (ε > 1000) in a wide temperature and frequency range were developed. In dielectric materials (1-x)BaTiO3–xNa0.5Bi0.5TiO3 (0.05 ≤ x ≤ 0.3) and (1 x)BaTiO3–x K0.5Bi0.5TiO3 (0.05 ≤ x ≤ 0.3) there is an increase in Curie temperature, a decrease in the dielectric constant and thedielectric losstangent with increase in x. It is shown that the materials containing potassium and sodium are characterized by a low change in dielectric constant Δε'/ε'Tc ≤ ± 15% in wide temperature ranges. It was found that the widest temperature range where Δε'/ε'Tc ≤ ± 15% in the system (1-x)BaTiO3–x Na0.5Bi0.5TiO3 (0.1 ≤ x ≤ 0.2) is observed at frequencies 1–10 and 105 Hz. While in the (1-x)BaTiO3–x K0.5Bi0.5TiO3 system, the widest temperature interval where Δε'/ε'Tc ≤ ± 15% appears in the frequency range of 102–104Hz (25–300°C) at x = 0.1 and 106 Hz (70–270°C) at x =0.2.The developed ceramic materials can be promising in the creation of high-temperature capacitors used in the drilling of geological exploration wells, the aerospace industry, and nuclear reactors. |
