Domain structure in a nematic layer under oscillatory Couette flow

The formation of a spatially modulated structure (domains) in a homeotropically aligned layer of a nematic liquid crystal (NLC) under an oscillatory Couette flow are described theoretically by using the hydrodynamic equations for an NLC which are linearized with respect to perturbations. The shear frequencies at which the phenomenon is determined by the inertial properties of the medium are considered. It is shown that the domain size is equal to the thickness h of an NLC layer and that the dependence of the threshold value of the shear amplitude u _th on the frequency ω and the layer thickness h is described by the expression u _th = const/(ωh²). The calculated results are compared with the experimental data.