Preparation of lead titanate thin films using Langmuir-Blodgett method

The Langmuir-Blodgett (LB) method is investigated as a process in the fabrication of ferroelectric thin films such as lead titanate. LB film was fabricated by depositing a monolayer prepared by stearic acid (C₁₇H₃₅COOH), lead chlorides (PbCl₂) and titanium bis(ammonium lactato)([CH₃CH(O-)CO₂NK₄] ₂Ti(OH)₂). As a conversion process from the LB film containing lead and titanium to an inorganic film, ultraviolet/ozone (UVO) treatment was found to be extremely applicable at a rate of about 4 min per monolayer. Subsequent rapid thermal annealing (RTA) resulted in a dense oxide thin film. The thickness of an oxide thin film converted from the LB film consisting of 301 layers was approximately 30 nm. Hence, it is considered that approximately 0.1 nm of the oxide layer is equivalent to the thickness of the film deposited by each cycle. From an X-ray diffraction pattern of the oxide specimen, a well-defined perovskite peak structure was observed. These results demonstrate the potential application of LB deposition for the preparation of an inorganic oxide film such as lead titanate.