Electrophysical properties of ceramics sintered at elevated temperatures BeO + 30 wt.% TiO2

Abstract

The electrophysical properties of ceramics based on BeO, in which micro and nanoparticles of TiO2 were introduced, were investigated by impedance spectroscopy in the frequency range of 100 Hz ‒ 100 MHz. In order to increase the density and conductivity, sintering of the initial ceramic components was carried out at the highest possible temperatures up to 1660 °C, followed by annealing in a hydrogen atmosphere at 800 °C. At the same time, TiO2 was strongly reduced with the formation of lower titanium oxides (Ti3O5) and titanium in the metallic state. When interacting with hydrogen, TiH2 is formed. For the first time, impurity phases were found in (VeO + TiO2) ceramics, which can significantly change the properties of its volume and surface. The resulting ceramics have a high through conductivity, which increases significantly after additional thermal combustion in a hydrogen atmosphere. It is established that the activation energy of the conductivity does not depend much on the concentration of TiO2 nanoparticles and decreases significantly in the low temperature region. By the method of constructing equivalent electrical circuits, the passage of the active and reactive components of the current through the complex internal structure of ceramics is modeled. Ill. 6. Ref. 11. Tab. 2.