Materials with high dielectric permeability on the basis of spontaneously polarized systems, lithium conductors and transition metal oxides

Materials with a high dielectric constant (e > 1000) based on complex oxides of spontaneously polarized systems, lithium-conducting systems, and oxides of transition metals were studied. It was shown in dielectric ceramics Ba(Ti,Sn)O3 the absence of significant dispersion of dielectric parameters (e and tg δ) in a wide frequency range from 1 to 105 Hz. The introduction of MnO2 and Al2O3-SiO2-TiO2 improves dielectric parameters and reduces sintering temperature. Obtained ceramic materials are characterized by high dielectric constant values e ~ 13000–16000 and low dielectric losses tg d ~ 0.05–0.06 (at 1 MHz). Synthesized solid solutions of La0.5Li0.5-xNaxTiO3 system, where x = 0 and 0.1, have high values e¢ > 104 at low frequencies (f ≤ 10 Hz). Dielectric properties of these materials are determined by the lithium ions mobility that increases with the rise of sodium content by increasing bottleneck size and decreases by the number of lithium vacancies reduction. The disadvantage of such materials is the decrease in dielectric constant with frequency increase. It was found that the ceramic СaСu3Тi4–xAlxО12-y-0.5xFy with x/y = 0.04/0.04 after sintering for 10 h is characterized by dielectric parameters: e¢ » 71000 (1 kHz) and tg d » 0.047. Introduction of aluminum (x/y = 0.04/0) or fluorine (0/0.08) in CCTO reduces dielectric losses (tg d » 0.044). The advantages of this type of material are a wide frequency range of high dielectric constant and relatively low dielectric loss. Synthesized materials can be used for the development of ceramic capacitors with high characteristics.