Microstructure and dielectric properties of strontium barium niobate ceramics synthesized by partial coprecipitation

Strontium Barium Niobate, Sr0.5Ba0.5Nb2O6 (SBN50), has been synthesized, for the first time, by partial coprecipitation of SrCl2 and BaCl2 on Nb2O5. Powder X-ray diffraction study shows tetragonal tungsten bronze phase formation at 1200 °C. Particle morphology and size of calcined powder has been examined using Transmission Electron Microscopy. The particle size of calcined powder ranges between 250 and 300 nm. The green compacts have been sintered at 1250, 1300 and 1350 °C and at each temperature for 6, 12 and 24 h, respectively. Effect of sintering time and temperature on dielectric properties has been investigated. Scanning electron microscopy has been used for grain morphology studies. Grains have been found to be tetragonal in shape and show variation in size for different sintering conditions. Highest dielectric constant (ε) has been observed for the pellet sintered at 1350 °C for 6 h. A variation in Tc from 93 to 119 °C has also been observed.