J. Phys. France 51, 1769-1776 (1990)
DOI: 10.1051/jphys:0199000510160176900

Smectic B : long range translational order and static shear instability. Nonlinear effects

I.S. Gersht et V.K. Pershin

Chelyabinsk State University, Lenin-Pr 77-43, 4S4 080 Chelyabinsk, U.S.S.R.

Abstract
Terms nonlinear with respect to the wave vector at translational oscillation frequencies have been taken into account for a layer system of uniaxial molecules and it has been proved that crystal order can coexist with a shear instability. On this basis a new model of smectic B phase has been proposed where the structure possessed long range translational order in all directions. At the same time interlayer dynamical shear modulus decreases at lower ω ap frequencies of an applied strain and equals zero in the static case (ωap → 0).

PACS
6130C - Molecular and microscopic models and theories of liquid crystal structure.
6210 - Mechanical properties of liquids.

Key words
elasticity of liquids -- long range order -- molecular orientation -- shear modulus -- smectic liquid crystals