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

Abstract

Sol-gel synthesis was attempted at room temperature by adding drop wise a clear solution (made by reacting BaCO₃ with glacial acetic acid) to an equi-molar solution of titanium tetrabutoxide in isopropanol (IPA) and acetic acid. The gelation occurred within 30 minutes. 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 ∼ 94%). XRD and SEM techniques were used for phase and microstructure analysis respectively. The room temperature relative permittivity (ε) of 1280 increased to 7200 (at Curie temperature of 127^∘C) at 1 kHz frequency. The dissipation factor (tanδ) ∼1.6% was observed in these samples. Also, the ferroelectric properties such as spontaneous polarization (Ps ∼ 13 μC/cm²), coercive field (E _c ∼4.0 kV/cm) and dielectric strength (∼34 kV/cm) are estimated for these samples. These performance parameters are compared with the available standard data from the literature.