溶胶-凝胶法制备(Ba,Sr,Ca)TiO_3薄膜及其介电调谐性能分析

Dielectric Tunability Properties of Sol-gel Derived (Ba,Sr,Ca) TiO_3 Thin Films

本文采用溶胶-凝胶法在Pt(111)/TiO2/SiO2/Si衬底上制备了(Ba0.6Sr0.4)1-xCaxTiO3(BSCT)(x=0,0.1,0.2,0.3,0.4)薄膜。XRD及SEM结果表明表明,薄膜结晶良好,形成单一的钙钛矿结构,没有明显的裂缝。薄膜厚度大约为500nm。从介电常数和直流偏压电场的关系曲线上并没有滞后现象,这说明BSCT薄膜处于顺电相。随着x的增加,薄膜的介电常数、介电损耗和调谐率都有所下降,而优值有所提高。J-V特性表明Ca的加入显著降低了薄膜的漏电流。

In this paper （Ba0.6Sr0.4）1-xCaxTiO3（BSCT） thin films was prepared on Pt （111） /TiO2/SiO2/Si substrates by using the Sol-gel techniques. The XRD and SEM observation reveals that BSCT forms the complete solid solutions in a single cubic perovskite structure and free of the detectable micro-porosities. The thickness of BSCT thin films was about 500nm. No hysteresis window was observed from the relationship of the dielectric constant and DC bias electric field, reflecting that BSCT thin films stay in the paraelectric state. The dielectric constant, tanδ and tunability decrease with increasing the amount of Ca, and the value of FOM increases. The leakage current of BSCT thin films decreases significantly with the Ca substitution.