Thermal fluctuations of the smectic layers in freely suspended thin liquid
crystalline films have been studied by the methods of X-ray diffraction and
reflectometry. The fluctuation dynamics is studied by the methods of photo
n correlation spectroscopy with the use of a source of coherent synchrotron
radiation. In freely suspended smectic films, the typical relaxation times
are of the order of several microseconds. In thin liquid crystalline films
, the simultaneous damped and oscillatory behavior was observed for the lay
er undulations. (C) 2001 MAIK "Nauka/Interperiodica".