Characterization of Barium Titanate: BaTiO3 (BT) Ceramics Prepared from Sol-Gel Derived BT Powders

Sol-gel synthesis was attempted at room temperature. The gelation occurred within 30 min. The as-dried gel was calcined at 750 C/6 h in air to obtain carbon-free BaTiO3 powders. The resulting BT powders were further pressed into pellets and sintered at 1280 C/4 h in air to get dense ceramics (density about 94%). XRD and SEM were used for phase and microstructure analysis respectively. The room temperature relative permittivity of 1280 increased to 7200 (at the Curie temperature of 127 C) at 1 kHz frequency. The dissipation factor of about 1.6% was observed in these samples. Ferroelectric properties such as spontaneous polarisation (about 13 microC/cm2), coercive field (about 4.0 kV/cm) and dielectric strength (about 34 kV/cm) were estimated for these samples. These performance parameters were compared with the available standard data from the literature.