Synthesis and Characterization of Nano-Particulate BaTiO₃ for Ceramic/Polymer Composite Capacitor

BaTiO₃ nano-particles with a size range of 20–70 nm were synthesized at 70 °C through a simple wet-chemical reactions between barium hydroxide octahydrate (Ba(OH)₂ · 8H₂O) and meta titanic acid (H₂TiO₃) in ethanol/water mixed solvent systems. It was found that the volume ratio of ethanol to deionized water is a key controlling parameter to determine the phase formation and particle size of BaTiO₃. Single-phase cubic perovskite BaTiO₃ started to be formed in solution containing above 40 volume percent of ethanol. From the field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analysis, the as-prepared BaTiO₃ exhibited the aggregated morphologies. The surface properties were characterized by the nitrogen adsorption isotherms curves. The effects of these aggregates on the electrical performance in BaTiO₃/epoxy nano-composites were also examined.