Characterization of Ba0.9Sr0.1TiO3 prepared by low temperature chloride aqueous synthesis

Ba0.9Sr0.1TiO3 powder was processed at 80 C by reacting Ti sol in aqueous solutions that contained BaCl2, SrCl2 and NaOH at atmospheric pressure. Well-crystallized, spherical, nanosizes powders were formed by this method. The powders were found to have a cubic structure, which was retained even after heating at 900 C. Sintering at 1400 C, led to the formation of a tetragonal structure with a secondary phase of Ba6Ti17O40. Abrupt grain growth was observed at 1400 C. The electrical response of the sample sintered at 1400 C has three electrically different regions. Each region of the sample is represented by different RC element. Element 1 (R1C1) is the most resistive and its capacitance ishigh (0.5 nFcm–1) indicating a thin region, probably the grain boundary. Element 2 (R2C2) shows a smaller resistance value compared to element 1. The capacitance value of element 2 is temperature-dependent and displays a Curie–Weiss behaviour, indicative of a ferroelectric material above Tc. The lower capacitance of C2 (15 pFcm–1) indicates that it is a much thicker region than element 1 and can be assigned as a ferroelectric bulk region. Element 3 is probably an electrode effect.