Dielectric properties of Aurivillius-type Bi4-xGdxTi3O12 ceramics

Abstract

The present work is aimed for dielectric investigation of undoped and gadolinium-substituted Aurivilliusstructure bismuth titanates Bi₄Ti₃O₁₂ (BIT) and Bi_2.5Gd_1.5Ti₃O₁₂ (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 Bi₄Ti₃O₁₂ and E_A = 0.98 eV for Bi_2.5Gd_1.5Ti₃O₁₂ [1].