Sol-gel法制备Al_2O_3-TiO_2复合介电膜层

Al_2O_3-TiO_2 composite dielectric film prepared by sol-gel method

用溶胶—凝胶法在腐蚀箔表面引入了TiO_2阀金属氧化物,随后在硼酸铵溶液中进行化成处理,获得了高介电常数的Al_2O_3-TiO_2复合介电膜层。以扫描电镜SEM、EDS能谱以及XRD能谱分析了氧化膜的表面及截面形貌、Ti元素的分布以及氧化膜的晶相。结果表明,经过550℃热处理后,锐钛矿型TiO_2已成功获得。随着涂Ti量的增加,腐蚀箔蚀孔孔径减小且被堵塞的几率变大,更易形成涂层缺陷。此外,氧化膜的升压曲线以及交流阻抗曲线的分析结果表明,当腐蚀箔表面涂Ti量为4.4 mg·cm^(-2)时,化成阶段消耗的形成电量最小,相对无Ti腐蚀箔减少了85.0%,与之对应的化成箔的比电容达到最大值(54.16μF·cm^(-2)),相对无Ti化成箔比电容增加了25.8%。

Al2O3-TiO2 composite film with high dielectric constant was prepared by sol-gel method in which TiO2 （valve metal oxide） was introduced onto the surface of etching aluminum foils, and then anodization treatment was carried out in ammonium borate solution. The morphology of surface and cross section, Ti-distribution and crystalline phase of the oxide film were characterized by means of SEM, EDS analysis and XRD. The results show that the antase TiOz is obtained after annealing at 550℃. Meanwhile, with the increasing of Ti coating amount, the pit diameter decreases, and the blocking probability of the pits increases, and thus the defects of the coating layer are readily formed. Furthermore, the anodization-time curve and EIS （electrochemical impedance spectra） indicate that when the Ti coating content is 4. 4 mg. cm -2（ metching aluminum area） , the electricity consumption in anodizing process is decreased by 85.0% compared with that of the specimen without Ti coating, and the capacitance performance is the maximum（54.16 μF. cm-2） , with an increase by 25.84% compared with that of the etching specimen without Ti coating.