PERIODIC DISTORTIONS IN LYOTROPIC NEMATIC CALAMITIC LIQUID-CRYSTALS

A theoretical tool to determine the dependence of the wavelength of pe riodic structures on the applied magnetic field in lyotropic liquid cr ystals in the nematic calamitic phase is proposed. It is assumed that the periodic structure experimentally found can be represented by a se quence of walls. Our calculations indicate that in order to describe t he measured behavior of the system above the Fredericks threshold the interaction between these walls must be taken into account. The streng th of these interactions and the ratio between the bend and twist elas tic constants are also determined.