Effect of antimony doping on properties of barium titanate ceramics

Abstract

Doping of BaTiO3 (BT) ceramics is very important to obtain required characteristics for different applications.

In this work, pure and Sb- doped barium titanate powders were prepared by polymeric precursors method (0.1 mol% Sb -BTS1, 0.3 mol% Sb -BTS3 and 0.5 mol% Sb -BTS5). Obtained powders were pressed and sintered at 1300oC for 8h in air atmosphere [1].

XRD results indicated only the presence of BaTiO3. In all sintered samples was detected well crystallized tetragonal phase. Figure 1. depicts SEM micrographs of sintered samples and it can be observed that antimony has significant effect on grain growth as well as on densification of obtained ceramics (higher then 90% TD) [2]. Temperature dependence of dielectric permittivity was established in the temperature range -200 to 175 oC and at frequencies of 100 KHz and 1 MHz (Figure 2.). The positions of all structural transitions are shifted to lower temperatures. In doped samples lower temperature transitions can not be clearly detected. Peaks become more broaden as the concentration of Sb increases. Barium titanate ceramic doped with 0.3 mol% Sb has the highest dielectric constant value and with further increase in dopant concentration dielectric constant become lower. Observed Curie temperatures and dielectric constant value at 100 KHz are given in the table.