Sol–gel synthesis, structural, and dielectric properties of terbium-modified ${\text{BaTiO}}_3$ ceramics

Tb-doped ${\text{BaTiO}}_3$ nanoparticles are prepared using the sol–gel method. The characterization was carried out using X-ray diffraction powder (XRD), Fourier transforms infrared spectroscopy (FTIR), and scanning electron microscopy spectroscopy (SEM). The FTIR analysis does not provide clear evidence on the effect of the doping amount. All diffraction peaks were perfectly matched with the pure phase of ${\text{BaTiO}}_3$. The tetragonal distortion factor is smoothly dependent on the doping amount. The grains decrease in size when Tb concentration is increased. The diffusion coefficient and phase transitions do not change greatly when introducing Tb into the crystal. Fitting values of $\gamma$ also support the evidence of normal ferro-paraelectric transition. Doped materials have a dielectric constant greater than undoped material, a meanwhile low loss is observed. The presence of Tb inhibits the formation of oxygen vacancies and promotes the stabilization of the oxygen-deficient system with the support of tetragonal phase formation during the sintering process.