Features of the production and study of electrophysical characteristics (BeO + TiO2)-ceramics by impedance spectroscopy

Abstract

The resulting electrically conductive two-component BeO ceramics with the addition of micro and nanocrystalline TiO₂ powder, which can be used as a material absorber of scattered microwave radiation in high-power electronic devices. The nature of the appearance of electrical conductivity and absorption of the microwave field in (BeO + TiO₂)-ceramics has not been completely established. The impedance spectroscopy method was the first to investigate the electrical and dielectric characteristics of this ceramics in the frequency range from 100 Hz to 100 MHz, depending on the presence of a micro- and nanosized TiO₂ phase in the composition of BeO ceramics. It has been established that the static resistance of ceramics with the addition of a TiO₂ nanopowder is significantly reduced compared with the resistance of the original ceramics with TiO₂ micropowder. It is shown that the real and imaginary components of the dielectric constant of the studied ceramics increase to abnormally large values as the frequency of the effective electric field decreases, and in the high frequency range f ≥ 10⁸ Hz, the process of dielectric relaxation begins, leading to an increase in the dielectric loss angle. The dielectric characteristics of ceramic samples are determined under blocking conditions for through conduction. The effect of TiO₂ micropowder additives on dielectric polarization processes with increasing frequency up to 12·10⁹ Hz is considered. Ill. 8. Ref. 26.