Preparation of lead titanate ultrathin film using langmuir-blodgett film as precursor

The Langmuir-Blodgett (LB) method is investigated as a process for the fabrication of ultrathin films of oxides such as lead titanate. LB film was fabricated by depositing a monolayer prepared from a fatty acid such as stearic acid (C₁₇H₃₅COOH) and a subphase containing lead chloride (PbCl₂) and titanium potassium oxalate (K₂TiO (C₂O₄)₂). For converting from an LB film containing lead and titanium to an inorganic film, ultraviolet/ozone (UVO) treatment was applied. Subsequent thermal annealing resulted in a dense oxide ultrathin film. The crystallographic orientation of lead titanate thin films was controlled by conditions of precursor preparation such as the molecular ratio of lead and titanium, pH value and/or temperature in the subphase and the surface pressure. An X-ray diffraction pattern of the thin film indicating a well-defined perovskite structure was observed. Moreover, the results demonstrated the potential application of LB deposition for controlling the crystallographic orientation oflcad titanate ultrathin films, particularly in the (111) or (101)(110) planes.