Abstract
Inorganic ferroelectric materials of Ba1-xPbxTiO3 powders were synthesized by firing and their application to the ferroelectric imaging was conducted. Firstly, the pellets of their solid solutions were prepared and the required material properties for the ferroelectric imaging were investigated. The investigation revealed that the ferroelectrics with lower dielectric constant and higher resistivity were poled by corona charging to the higher extent, leading to the development of the higher pyroelectric surface potential. The best suited derivative in the present system was obtained at x = 0.25, Ba0.75Pb0.25TiO3 (relative dielectric constant = 420, resistivity = 8.0×1013Ωcm), and its pyroelectric potentials were -0.23 and +0.25V/μm for the positive and negative poling treatments, respectively.
Secondly, the more advanced materials, the composite films of Ba0.75Pb0.25TiO3 with polyvinylbutyral (PVB), were prepared and their feasibility to be used as a ferroelectric imaging medium was investigated. As a result, the composites were found to have ferroelectric and pyroelectric properties superior to those of the corresponding solid solutions, and developed higher pyroelectric potentials: the pyroelectric potentials of -1.2 and +1.6V/μm for the positive and negative poling treatments, respectively, were obtained when the Ba0.75Pb0.25TiO3 was prepared by firing (1000°C, 3h)twice or three times and the resultant composite film (ca. 80μm thick)was heated at 140°C. The charged film attracted toner particles according to the positional distribution of the pyroelectric potentials to give visible images.
