Crack-free nanostructured BaTiO3 thin films prepared by sol–gel dip-coating technique

Abstract

In this report, crack-free nanostructured barium titanate thin films are prepared by a sol–gel processing method. Glacial acetic acid, barium acetate, titanium tetraisopropyl alkoxide, 2-propanol and deionized water are used as precursors for preparing stable precursor solution. Then very thin films (thickness=26nm) are deposited on fused silica substrates. In order to prepare crack-free thin films of BaTiO3, much attention is given to solvent evaporation process and a controlled pre-drying process is developed. It is found that the control of the process, especially in the initial stage of drying process is crucial and important for preparation of the crack-free ultrathin nanostructured BaTiO3 films. In our proposed method, as-deposited thin films undergo a slow drying process in saturated vapor pressure of the precursor solution. The above process leads to the formation of crack-free nanostructured BaTiO3 thin films. Structure and morphology of the thin films are characterized by XRD, SEM and AFM characterization methods. Results indicate that the thin films are crack-free with a dense nanogranular structure.