BaTiO<sub>3</sub> Functional Ceramics Thin Film Prepared by Self-Assembled Monolayers

Abstract

BaTiO3 thin film was prepared by the self-assembled monolayers technique and liquid phase deposition. The effects of pH values and the deposition temperature on the formation of BaTiO3 film were studied. The results showed that the Si substrate was in the precursor solution with 0.025mol/L (AHFT/BN/BA=1:1:3) and pH= 1.5. At 45°C deposited for 8h and annealed at 600°C for 2h, the BaTiO3 film with higher crystalline was prepared on the functionalized Si substrate. XRD and SEM tests showed that the film deposited in the precursor solution with different pH values appeared BaTiO3 characteristic peaks on the surface of every crystal. As pH values increased to 1.5 from 0.5, the strength of the film diffraction peak increased. But the width of the peak became smaller and the crystalline increased. When pH value was 2, due to the self-polymerized deposition of [Ti(OH)6]2-, it was easy to form the larger particles on the substrate. When the deposition temperature was 45°C, the acicular BaTiO3 film formed with the regular order and homogeneous planeness on the substrate. When the deposition temperature was between 55°C and 60°C, the dewatering and polymerizing speed between [Ti(OH)6]2- ions was higher than that between [Ti(OH)6]2- and -OH. The adsorption of the film to the Si substrate was weakened. It was easy for the film to fall off.