Microstructure and electrical properties of Bi₂O₃ excess Bi_3.25La_0.75Ti₃O₁₂ ferroelectric ceramics

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• 作者：Yunyi Wu ; Duanming Zhang ; Jun Yu ; Yunbo Wang
• 关键词：Ceramic ; Raman spectroscopy and scattering ; X-ray diffraction topography ; Ferroelectricity
• 刊名：Materials Chemistry and Physics
• 出版年：2009
• 出版时间：15 January 2009
• 年：2009
• 卷：113
• 期：1
• 页码：422-427
• 全文大小：630 K

文摘

Bi_3.25La_0.75Ti₃O₁₂ (BLT) ceramic samples derived from different amount of initial Bi₂O₃ excess were prepared by conventional solid-state method. The microstructures and electrical properties of BLT ceramic samples are strongly dependent on the initial Bi₂O₃ excess content, as examined by XRD, SEM, Raman spectra, P-E hysteresis loops and dielectric, etc. Appropriate initial Bi₂O₃ excess reduces the leakage current and loss tangent and therefore improves polarization of BLT ceramics, while too much initial Bi₂O₃ excess leads to a reduction in polarization and an increase in coercive field. The best polarization behavior was observed for the BLT ceramic sample derived from 8 mol % initial Bi₂O₃ excess, where a remnant polarization (2P_r) of 20.4 μC cm⁻² and coercive field (E_c) of 38 KV cm⁻¹ were shown. A similar change in dielectric constant with the increase of initial Bi₂O₃ excess content was also observed and the highest dielectric constant of 142.9 was obtained for the BLT ceramic derived from 8 mol % initial Bi₂O₃ excess.