Properties of La and V codoped Bi4Ti3O12 thin film prepared by sol-gel method

Abstract

Bi4Ti3O12（BIT） and Bi3.25La0.75Ti2.97V0.03O12（BLTV） thin films were fabricated on the Pt/TiO2/SiO2/p-Si（100） substrate using sol-gel method. The effect of La and V codoping on the structural and electrical properties of BIT thin films was investigated. BIT thin film exhibits predominantly c-axis orientation while BLTV thin film shows random orientation. Raman spectroscopy shows that TiO6 （or VO6） symmetry decreases and Ti—O （or V—O） hybridization increases with V substitution. The residual polarization of BLTV thin film is 25.4 μC/cm2, which is larger than that of BIT thin film （9.2 μC/cm2）. BLTV thin film also shows excellent fatigue endurance and low leakage current characteristics, which implies the oxygen vacancies are suppressed by La and V codoping in the thin films.