QUANTITATIVE CALCULATION OF SPONTANEOUS POLARIZATION IN FERROELECTRICLIQUID-CRYSTALS

We compute the spontaneous polarization, P, exhibited by a class of fe rroelectric liquid crystals (FLCs) with systematically varying structu res in an effort to critically test a recently proposed model [D. J. P hotinos and E. T. Samulski, Science 270, 783 (1995)] which implies tha t polarity is indigenous to tilted smectic phases. We evaluate the fir st and second rank segmental order parameters of the FLC compounds by taking into account the essential features of molecular structure and conformation subjected to the general stratification constraints in th e model smectic FLC. The results compare favorably with available expe rimental values of P and bond order parameters obtained from NMR measu rements. (C) 1997 American Institute of Physics.