Lowering of sintering temperature and microwave dielectric properties of BaTi4O9 ceramics prepared by the polymeric precursor method

Low temperature sintering and microwave dielectric properties of barium polytitanate (BaO–4TiO2) ceramics prepared by means of polymeric precursor route based on the Pechini process were investigated. Pure and fine BaTi4O9 powders with particle sizes of 100–200 nm were derived by thermal decomposition of amorphous gel precursor (above 750 °C). They formed single orthorhombic BaTi4O9 phase and showed fine and well-dispersed by XRD and SEM observation. The high sintering ability of the prepared powders enabled the fabrication of dielectric ceramics at low sintering temperatures (1200–1300 °C). The well-sintered BaTi4O9 ceramics with high relative densities (95%) were found to show excellent microwave dielectric properties compared to those prepared by conventional method at the same sintering temperature.