Preparation of titanium dioxide and barium titanate nanothick film by Langmuir–Blodgett technique

Abstract

The TiO 2 and BaO(TiO 2) x thin film was prepared by the Langmuir–Blodgett (LB) technique. The mixture of octadecyl polymaleicate and tetrabutoxytitanium was spread on the surface of water subphase, then transferred onto substrates. The obtained LB multilayer was converted into a nano-thick TiO 2 film by calcination at 500°C for 30 min. When an appropriate amount of BaCl 2 was added into a water subphase, it was co-transferred onto a LB multilayer film. After calcination at the same condition, BaO(TiO 2) x thin films with different ratios of x could be obtained by adjusting the pH value of the water subphase. The Fourier transform infrared spectroscopy and X-ray photoelectron spectra measurements were used to confirm the formation of TiO 2 and BaO(TiO 2) x thin films. The integrated peak area in X-ray photoelectron spectra gave the atomic ratio of Ti/O and Ti/Ba. The surface morphology of the LB multilayer before and after calcination was investigated by atomic force microscopy. The image showed that the smooth and high cover surface of TiO 2 and BaO(TiO 2) x thin films were obtained after calcination. The rms roughness for a 21-layer film after calcination was approximately 25 Å, which was less than that of before calcination of approximately 45 Å. The resulting particle size was approximately 0.05 μm and almost uniform.