The semi-phenomenological model of antiferroelectricity in chiral smectic liquid crystals - I. The structure of short pitch modes and a thermodynamical approach

The development of the model of short pitch modes for ferro-, antiferro- an d ferri-electric chiral smectic liquid crystals is presented. Prediction of the structures of the subphases is made. The pure short pitch mode having an n-ray star structure of the n-layers of the unit cell appears to possess antiferroelectric properties. Ferrielectricity is assumed to arise as a re sult of the coexistence and interaction of the short pitch mode with a long pitch helix. Corresponding polarizational properties and fine structure of the peaks of the resonant X-ray scattering from such structures are calcul ated.