Particularities of the Dynamics of Linear Domains in Liquid Crystals under a Binary Acoustic Action

Abstract

The dynamical properties of a system of linear domains induced by shear oscillations in a planar layer of a nematic liquid crystal under the joint action of shear and piston oscillations at frequencies in the audio range, have been studied experimentally. The phenomenon of spatial modulation of the domains of an initial system along their axis under the piston oscillations producing periodic layer compression is investigated for the case where the directions of the director in a mesophase layer and the shear oscillations coincide. A relationship between the period of secondary two-dimensional structures at the effect threshold and the layer thickness as well as oscillation frequency is established. It is shown that the formation mechanism of these structures can be interpreted on the basis of a known phenomenological model, according to which the instability of the initial system of these linear domains is caused by the “mismatch” between the real period of domains and its optimal value, which varies jointly with the variations in the thickness of a periodically compressed layer.