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

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 (ω ap →0)