Dielectric properties of substituted BaTiO3 synthesized by the coprecipitation method
Various substituted BaTiO3 materials were synthesized using the co-precipitation method. BaCO3 powders as well as carbonate powders of Sr, Ca, Bi, and nitrate powders of Pb were used to synthesize various monosubstituted BaTiO3 materials of composition Ba1-xRxTiO3 (where R = Bi, Sr, Ca, Pb and x = 0.25, 0.50, 0.75, 1.0). Appropriate amounts of the Ba and substituent precursors were mixed in nitric acid. TiCl4, was then added to the mixture. Coprecipitation was achieved by slowly adding ammonium hydroxide while continuously stirring the mixture. The precipitates were washed, dried, and then calcined at 700°C for 8 hrs. The resulting powder was then formed into pellets and sintered at 1000°C for 12 hrs. A total of 16 samples were made. Characterization tests used were scanning electron microscopy, capacitance measurements using a bridge circuit, resistivity measurements, and x-ray diffraction. The dielectric constant and dielectric loss were calculated from the capacitance data.