Effect of Sintering Time on Dielectric Properties of Barium Titanate and Nb Doped Barium Titanate

Abstract:

Barium titanate (BaTiO₃) with its perovskite structure is a promising dielectric material for many applications such as transducers, actuators, high-k dielectrics and multilayer ceramic capacitors (MLCC). In this study, we have investigated the effect of sintering time on dielectric properties of BaTiO₃ and Nb-doped BaTiO₃. BaTiO₃ was doped with 0.3 mol % niobium oxide (Nb₂O₅). At first, nanosized pure BaTiO₃ and Nb₂O₅ doped BaTiO₃ were milled, dried and pressed into pellets to prepare green samples. Then, the samples were sintered at 1275°C for different time periods ranging from 2 to 5 hrs. Single stage sintering was adopted for the densification of prepared samples. Microstructure of the sintered samples was investigated employing Field-emission scanning electron microscope (FESEM). Dielectric properties of the samples were measured using an impedance analyzer. Finally, a correlation was established between the dielectric properties of the sintered samples and their microstructure. Nb has shown to provide strong inhibiting effect after sintering the samples in the range of 2 to 5 hours at 1275°C thereby, resulted in higher dielectric properties of doped BaTiO₃ ceramics compared to that of pure BaTiO₃. The best room temperature dielectric constant of 7200 was obtained for Nb doped BaTiO₃ sintered at 1275°C for five hours. Such improved dielectric constant is attributed to the optimum grain size of about 1 micron at this sintering temperature.

• Periodical: Applied Mechanics and Materials (Volume 860)
• Pages: 129-133
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.860.129
• Online since: December 2016
• Authors: M.K. Rahman*, M.F. Hossain, Kazi Mohammad Shorowordi, M.A. Matin
• Keywords: Barium Titanate, Dielectric Properties, Grain Size, Sintering Time

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