【摘要】 采用共沉淀法制备了平均粒径约为191nm的Bi_3.5La_0.5Ti₃O₁₂粉末。对比研究了传统烧结、快速升温两步烧结和快速升温一步烧结三种烧结工艺对处于近纳米级Bi_3.5La_0.5Ti₃O₁₂坯体的致密化、最终陶瓷的显微结构以及介电性能的影响。研究结果表明,烧结过程的保温阶段,相同的保温时间下,快速升温两步烧结工艺在第二阶段保温温度比其他两种烧结工艺降低30℃的情况下制备的试样的密度较高,平均晶粒尺寸最小;传统烧结工艺制备的试样密度低于其它两种工艺的试样密度,且试样晶粒尺寸最大;快速升温一步烧结工艺制备的试样密度最大。介电测试结果表明,采用不同烧结升温工艺均保温8小时制备的试样的介电常数随着试样晶粒尺寸的增加而增大,居里温度点随着晶粒尺寸的增加而向高温方向移动。更多还原

【Abstract】 Bi_3.5La_0.5Ti₃O₁₂ powder was prepared by the co-precipitation method,and the average particle size of Bi_3.5La_0.5Ti₃O₁₂ powder is 191 nm.Comparatively study on the effects of conventional sintering,rapid heating up two-step sintering and rapid heating up one-step sintering of three sintering processes on the densification,the final microstructure and dielectric properties of Bi_3.5La_0.5Ti₃O₁₂ ceramic.The results show that during the holding period of the sintering process,and under the same holding time,the sample made by the rapid heating up two-step sintering which holding temperature is 30℃ lower than the other two kinds of method in the second stage,has a high density.The average grain size of the sample made by the rapid heating up two-step sintering is smaller than that of the sample prepared by the other two sintering processes.The density of the sample prepared by traditional sintering process were lower than the density of the sample made by the other two kinds of method,while the grain size is larger than the other two methods.The density of the sample prepared by rapid heating up one-step sintering is higher than the other two kinds of methods.The dielectric test results show that the dielectric constant of different process heat for eight hours of preparation of Bi_3.5La_0.5Ti₃O₁₂ ceramic samples increases with the increase of the grain size,the Curie temperature move to higher temperature with the increase of grain size.更多还原