溶胶-凝胶法制备CaCu3Ti4O12粉体及其电性能

摘要

利用溶胶-凝胶法制备CaCu3Ti4O12粉体,采用差热分析、X射线衍射、扫描电子显微镜等技术进行表征,并探讨CaCu3Ti4O12粉体的烧结特性及电性能.结果表明,干凝胶经750℃低温煅烧可获得粒径分布较窄、平均粒径为80～100 nm的CaCu3Ti4O12粉体.CaCu3Ti4O12陶瓷在1000℃时实现致密烧结,比固相反应法制备的粉体烧结温度降低100～200℃,具有较宽的烧结温区.溶胶-凝胶法制备的陶瓷经1050℃烧结2h,获得优良的电性能,相对介电常数为20190,介电损耗为0.022,非线性系数为4.530.%CaCuTi4O12 powders were prepared by sol-gel method and characterized by TG-DTA, XRD and SEM. The sintering characteristics and electric properties of CaCu3Ti4O12 powders were investigated. The results show that CaCu3Ti4O12 powders with a diameter of 80~100 nm and narrow particle size distribution can be obtained by low temperature calcining the xerogel at 750 ℃. CaCu3Ti4O12 ceramics made from the powder can be sintered at 1 000 ℃ to acquire the dense structure. The sintering temperature is lower by 100~200 ℃ than the sample obtained by solid reaction method using micron powders. The sintering range of CaCu3Ti4O12 ceramics is also widened. At the sintering temperature of 1 050 ℃ for 2 h, CaCu3Ti4O12 ceramics made from powder have good electric properties. The relative dielectric constant value is 20 190, loss tangent is 0.022, and nonlinear coefficient is 4.530.