(Na1/2Bi1/2)Cu3Ti4O12陶瓷的微观结构和电学性质

利用固相反应法在不同烧结温度条件下制备了一系列(Na_1/2Bi_1/2)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 关键词： 高介电材料 介电性质 复阻抗 内阻挡层电容

Microstructures and electrical properties of (Na1/2 Bi1/2)Cu3Ti4O12 ceramics

A series of (Na_1/2Bi_1/2)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 CaCu₃Ti₄O₁₂ceramics. 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.