(Na_(1/2)Bi_(1/2))Cu_3Ti_4O_(12)陶瓷的微观结构和电学性质  

Microstructures and electrical properties of (Na_(1/2)Bi_(1/2))Cu_3Ti_4O_(12) ceramics

作　　者：陈戈[1] 张家良[1] 郝文涛[1] 谭永强[1] 郑鹏[1] 邵守福[1] 

机构地区：[1]山东大学物理系,济南250100

出　　处：《物理学报》2010年第5期3509-3515,共7页Acta Physica Sinica

基　　金：国家重点基础研究发展计划(973)项目(批准号:2007CB607504);教育部"新世纪优秀人才支持计划"项目(批准号:NCET-06-0587)资助的课题~~

摘　　要：利用固相反应法在不同烧结温度条件下制备了一系列(Na1/2Bi1/2)Cu3Ti4O12(NBCTO)陶瓷样品,研究了它们的晶体结构、微观组织结构、介电性质和复阻抗及其随温度的变化.实验发现NBCTO陶瓷所呈现出的电学性质与CaCu3Ti4O12陶瓷相应的电学性质非常类似.烧结温度为990℃至1060℃范围的NBCTO陶瓷样品室温下的低频介电常数ε′均大于10000.随着烧结温度的提高,ε′呈现出先增大后减小的变化,晶粒尺寸展现出与介电常数相同的变化趋势.不同烧结温度条件的NBCTO陶瓷样品所呈现出的电学性质变化之间有非常大的差异,但其中也有着一些共同的特征.在40Hz至10MHz的测试频率范围内,低温和室温下的介电频谱中只能观测到一个介电弛豫,而在较高温度下则可以观察到两个介电弛豫.A series of （ Na1/2 Bi1/2 ） Cu3Ti4O12 （ NBCTO） ceramics were prepared by solid-state reaction at different sintering temperatures. The crystal structure,microstructures,dielectric properties and complex impedance and the corresponding temperature dependences were investigated. It has been revealed that the NBCTO ceramics has quite similar electrical properties with those previously found in CaCu3Ti4O12 ceramics. The NBCTO ceramics prepared at sintering temperatures between 990℃ and 1060℃ exhibit low-frequency ε＇ larger than 10000 at room temperature. With the increasing of sintering temperature,both ε＇ and the grain size in microstructure first increase and then decrease. Although large difference is observed in their dielectric properties and complex impedance for the various NBCTO ceramics,there exist some common features. Whereas only one dielectric relaxation is seen at room temperature or lower temperatures,two are seen in the dielectric spectra within the measured frequency range of 40 Hz—10 MHz at higher temperatures.

关 键 词：高介电材料 介电性质 复阻抗 内阻挡层电容 

分 类 号：O482.4[理学—固体物理]