Ferro- and antiferroelectric properties of Langmuir-Blodgett films composed of mesogenic bent-core molecules

A bent-core mesogenic compound was used for preparation of thin solid Langmuir films (25-100 nm) that were transferred onto glass substrates and supplied with Al electrodes evaporated in vacuum. The Langmuir-Blodgett technique allowed us studying the thin polar films of the banana-shaped liquid crystal in sandwich geometry that keep amazing integrity on heating, even up to high-temperature B-2 phase, and show antiferroelectric and ferroelectric properties, which depend on film thickness. The magnitude of the measured switched polarization (400 nC/cm(2)) is similar to that of the bulk material. The strong confinement of film results in high coercive field which reaches the value of 10(8) V/m for the thinnest film. The investigations of dielectric properties are reported.