TiO2晶型对FeTiTaO6陶瓷介电特性的影响

分别选取纯金红石结构和金红石与锐钛矿混合结构的TiO2为钛源,通过传统固相法制备FeTiTaO6陶瓷。利用X射线衍射、扫描电子显微镜等手段对比表征了2种钛源条件下合成FeTiTaO6的相结构和微观形貌,并测试了二者的介温谱。结果显示,以纯金红石TiO2为原料合成的FeTiTaO6陶瓷有明显的介电弛豫特性,而以含有锐钛矿的TiO2为原料合成的FeTiTaO6陶瓷没有介电峰出现。原因是由于在煅烧阶段不同晶型TiO2之间发生结构转变,使制得的陶瓷粉体反应活性不同,进而影响陶瓷烧结的热力学进程,并导致陶瓷的介电性能出现差异。

Effect of Crystal Structure of TiO2 on Dielectric Behavior of FeTiTaO6 Ceramics

FeTiTaO6 ceramics were prepared by conventional mixed oxide method, using the pure rutile and mixture of rutile with anatase as titanium source. The phase formation and morphological evolution of FeTiTaO6 were investigated by XRD and SEM. The dielectric properties were also measured. The results show that with pure rutile as titanium source, the prepared FeTiTaO6 ceramics exhibit a strong relax ferroelectric feature, while using the mixture of rutile with anatase as titanium source, no dielectric peak appears in ceramics. Due to the difference between the two crystalline TiO2, the phase transformation occurs in the calcining process and the prepared FeTiTaO6 powders have the different reaction activity, which further affects the thermodynamic process of ceramic sintering, resulting in the different dielectric behavior.