Effect of Sintering Temperature on Structural and Dielectric Properties of Bi and Li Co-Substituted SrTiO3

Sintering is an important factor that affects the microstructure development in ceramics. In this work, Bi and Li co-substituted Strontium Titanate (ST) ceramics samples sintered at different temperatures are prepared and analyzed by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). XRD was used to detect phase structure of the sintered samples and SEM was used for microstructure analysis. Dielectric properties of Bi and Li co-substituted SrTiO3 samples were measured using Agilent 4294A Impedance analyzer in the frequency range 40 Hz to 5 MHz at room temperature. The result reveals that the dielectric constant of Bi and Li co-substituted SrTiO3 ceramics increases with increasing sintering temperature up to 1250 degrees C and then decreases beyond that. The highest value of dielectric constant obtained is 860 at 1KHz frequency and lowest dielectric loss observed is 0.04 at the same frequency for samples sintered at 1250 degrees C. Also the grain size increases with increase of sintering temperature.