EFFECT OF SINTERING TEMPERATURE ON THE MICROSTRUCTURE AND MICROWAVE DIELECTRIC PROPERTIES OF STRONTIUM TITANATE (SrTiO3) CERAMICS

Abstract

In this study, microstructure and microwave dielectric properties of strontium titanate (SrTiO₃) ceramics prepared via conventional solid state reaction route were investigated. The starting materials used for the preparation of SrTiO₃ were strontium carbonate (SrCO₃) and titanium oxide (TiO₂). SrTiO₃ ceramics were calcined at 1100 °C and sintered at 1200 °C, 1300 °C, and 1400 °C respectively. Identification of crystalline compounds of SrTiO₃ ceramics were analyzed using X-ray Diffraction (XRD). Microstructure of SrTiO₃ ceramics were then characterized by Field Emission Scanning Electron Microscope (FE-SEM). The microwave dielectric properties of SrTiO₃ were measured in the frequencies range from 1 MHz to 1.5 GHz using Agilent RF Impedance/Material Analyzer 4192B. From the XRD patterns of SrTiO₃ ceramics, it showed that SrTiO₃ ceramics were in crystalline structure after sintering. SrTiO₃ ceramic sintered at 1400 °C has larger grain size with lower porosity. Loose and porous structure was observed for SrTiO₃ ceramic sintered at 1200 °C. For SrTiO₃ ceramic sintered at 1400 °C, it was observed that the dielectric constant was the highest. Lower dielectric constant was observed for SrTiO₃ ceramic sintered at 1300 °C.