Dielectric properties of Er2O3 doped BaTiO3 ceramics

Abstract

In this paper, the microstructure and dielectric properties of Er-doped BaTiO3 ceramics were investigated. The concentrations of dopant, Er2O3, in the tested samples were ranged from 0.01 to 1.0at% Er. Conventional solid state reaction was used to obtain modified BaTiO3 ceramics. The samples were sintered at temperatures of 1320°, 1350° and 1380 °C for 4 hours. SEM analysis of Er/BaTiO3 doped ceramic showed, that samples doped with a smaller concentration of additive (0.01 and 0.1 at%) characterized a homogeneous microstructure with a grain size from 10 to 25 µm. For samples doped with a larger concentration of additives (0.5 and 1.0 at%) characteristic grain size ranged from 7 to 15 μm. Dielectric properties were measured in the frequency range of 20 Hz to 1 MHz at room temperature. Sample doped with Er 0.01 at%, and sintered at 1380 °C is characterized with a relatively high value of dielectric constant (ɛr=947) at room temperature. For samples doped with the same concentration of Er and sintered at 1320 °C temperature characteristic is a lower value of the dielectric constant (ɛr=551). With the increase of sintering temperature, the dielectric constant of the samples increased, and the highest value were measured for samples sintered at 1380 °C. Also, for all investigated samples were measured resistivity and the highest values of electrical resistivity was obtained for samples sintered at temperatures of 1320 °C.

Keywords

• BaTiO3
• sintering
• microstructure
• dielectric characteristics