Dielectric Properties of Chromium-Containing Bismuth Titanate Ceramics with the Layered Perovskite Type Structure.

By the method of dielectric spectroscopy the complex oxides of bismuth titanate with a structure of layered perovskite doped by Cr in accordance with the stoichiometric formulas Bi4Ti2.98Cr0.02O11.99, Bi4Ti2.5Cr0.5O11.75, Bi4Ti1.8Cr1.2O11.4were studied. Shown the existence a critical concentration x (0.5<x<1), above which there is a significant change in the dielectric properties associated with the change in the number of perovskite-like layers. It was found the correlation between the concentration of the substitution atoms Cr and grain size on the sample surface. Phase transitions in the temperature range of 660–680°C and at about 920°C were detected by the of DSC method. [ABSTRACT FROM AUTHOR]