Dynamic and correlation properties of solid supported smectic-A films

Dynamic properties and layer displacement-layer displacement correlation functions of the smectic-A films on a substrate are investigated. The eigenfrequencies spectrum and eigenmotions of the film are calculated within the framework of a discrete model. It was found that the static as well as dynamic properties of freely standing and solid supported smectic-A films differ significantly. In particular, the acoustic mode is absent in the films on a substrate and the surface tension is not essential for the film dynamics. The correlation length of the spatial layer displacement correlation functions is finite for films on a substrate in contrast to the free standing films. An effect of thermal fluctuations on the specular and diffuse x-ray scattering was analyzed.