Thermal generation of confocal domains in a smectic a liquid crystal

The effects of vacuum-deposited SiOx alignment layers on the thermal generation of focal conic centers in a smectic A liquid crystal were investigated using controlled thermal cycles. Surface defects were found to promote focal conic formation. Focal conic density increases with cooling rate for a given alignment layer, and with the deposition angle of the alignment layer for a fixed cooling rate. An attempt was made to fit these findings to heterogeneous nucleation theory in an effort to better understand the effects of selected thermodynamic properties on the focal conic formation process.