Effects of buffer layer on the dielectric properties of BaTiO 3 thin films prepared by sol–gel processing

Abstract

Ferroelectric BaTiO 3 (BT) thin films were deposited on Pt/Ti/SiO 2/Si substrates by sol–gel technique. The thickness of the La 0.5Sr 0.5CoO 3 (LSCO), serving as a buffer layer, was varied from 0 nm to 210 nm, to study the dependence of dielectric properties of the BT thin films on the buffer layer thickness and stress. The influence of buffer layer thickness on the phase and microstructure of the thin films was also examined. Dielectric properties of the thin films were investigated as a function of temperature and direct current (dc) electric field. The results showed that the LSCO buffer layer strongly influenced the microstructure and the dielectric properties of the films. The BT thin film with 150 nm thickness LSCO buffer layer had the least loss, smallest leakage current and largest dielectric constant.