Characterization of Ba_0.9Sr_0.1TiO₃ prepared by low temperature chloride aqueous synthesis

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• 作者：Srimala Sreekantan ; Ahmad Fauzi Mohd Noor ; Zainal Arifin Ahmad ; Radzali Othman ; Anthony West and Derek Sinclair
• 刊名：Journal of Materials Science
• 出版年：2007
• 出版时间：April, 2007
• 年：2007
• 卷：42
• 期：7
• 页码：2492-2498
• 全文大小：296 KB

文摘

Ba_0.9Sr_0.1TiO₃ powder was processed at 80¡ãC 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¡ãC. Sintering at 1400¡ãC, led to the formation of a tetragonal structure with a secondary phase of Ba₆Ti₁₇O₄₀. Abrupt grain growth was observed at 1400¡ãC. The electrical response of the sample sintered at 1400¡ãC has three electrically different regions. Each region of the sample is represented by different RC element. Element 1 (R ₁ C ₁) is the most resistive and its capacitance ishigh (0.5 nFcm−1) indicating a thin region, probably the grain boundary. Element 2 (R ₂ C ₂) 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 T _c. The lower capacitance of C ₂ (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.