溶胶–凝胶法制备Au-BaTiO_3纳米复合薄膜及其介电性能  

Dielectric Properties of Au-BaTiO_3 Nanocomposite Films Prepared by Sol-Gel Method

作　　者：武英杰[1,2] 王海玲[2] 宁兴坤 王占杰[1,2,3] 王强[3] 

机构地区：[1]东北大学材料与冶金学院,沈阳110819 [2]中国科学院金属研究所沈阳材料科学国家实验室,沈阳110016 [3]东北大学材料电磁过程研究教育部重点实验室,沈阳110819

出　　处：《无机材料学报》2015年第2期207-213,共7页Journal of Inorganic Materials

基　　金：国家自然科学基金(51172238)~~

摘　　要：采用溶胶–凝胶法在Pt/Ti/Si O2/Si基板上制备了Au-Ba Ti O3纳米复合薄膜,并且对其晶体结构、微观组织和介电性能进行了研究。结果表明,Au在复合薄膜中以直径为5~22 nm的Au纳米粒子弥散地分布在Ba Ti O3基体中。Au的添加量对复合薄膜的介电性能和表面形貌有很大影响,其最佳添加量约为5mol%。复合薄膜经过550℃的低温退火已经完全结晶为钙钛矿相,其介电常数与700℃退火的纯Ba Ti O3薄膜的相当。在Au-Ba Ti O3复合薄膜的结晶过程中,一方面,Au纳米粒子可能促进了中间相的分解;另一方面,Au纳米粒子诱发了钙钛矿相的异质形核,促进了Ba Ti O3的结晶化。因此,Au纳米粒子大幅度地降低了复合薄膜的退火温度,并显著提高了复合薄膜的介电性能。Au-BaTiO3 nanocomposite thin films were prepared on Pt/Ti/SiO2/Si substrates by a Sol-Gel method and their crystal structure, microstructure and dielectric properties were investigated. Au nanoparticles with diame- ter of 5-22 nm are distributed in the BaTiO3 matrix. Au concentration has great effects on the surface morphology and dielectric properties of the composite thin films, and the optimal concentration of Au is about 5mo1%. The composite thin films have crystallized into the perovskite phase after annealing at 550℃, and their dielectric con- stant is equivalent with that of the pure BaTiO3 thin films annealed at 700℃. The enhanced crystallization of Au-BaTiO3 composite film is attributed to the addition of Au nanoparticles, which can promote the decomposition of the intermediate phase and induce a heterogeneous nucleation of the perovskite phase. Thus, the annealing tem- perature of the composite films is drastically reduced and their dielectric properties are improved significantly with the addition ofAu nanoparticles.

关 键 词：Ba Ti O3 纳米复合薄膜 溶胶–凝胶法 介电性能 结晶化 

分 类 号：O469[理学—凝聚态物理]