Dielectric properties of Aurivillius-type Bi_4-<i>x</i>Gd_<i>x</i>Ti₃O₁₂ ceramics

Abstract

The present work is aimed for dielectric investigation of undoped and gadolinium-substituted Aurivilliusstructure bismuth titanates Bi 4 Ti 3 O 12 (BIT) and Bi 2.5 Gd 1.5 Ti 3 O 12 (BGT). The measurements were performed as a function of both frequency and temperature in the frequency range of 20 Hz -1 MHz and in the temperature range of 30-1100 K. Obtained results can be divided into two parts: the low temperature part, where the glass like dispersion occurs, and the high temperature part, where high electrical conductivity dominates. The activation energies for the presumably oxygen vacancies migration-related conductivity is E A = 0.73 eV for Bi 4 Ti 3 O 12 and E A = 0.98 eV for Bi 2.5 Gd 1.5 Ti 3 O 12 [1].