Anticlinic coupling between layers of an antiferroelectric liquid crystal

The anticlinic interlayer: coupling coefficient U was evaluated as a functi on of temperature for a pitchccompensate did crystal by optical observation of the electric field-induced optic mode. U was found to exhibit an unusua l "S-shaped" dependence on temperature, with values ranging between 0.4 X 1 0(4) and 2.2 x 10(4) erg cm(-3) over a 10 degrees C temperature range below the smectic-A-smectic-C-A(*) phase-transition temperature. The results are in good agreement with estimates for U based upon the threshold field for the onset of solitary waves, and provide strong support in the low-field re gime for the single Fourier component model proposed by Li et al. [Phys. Re v. B 52, R13 075 (1995)]. [S1063-651X(99)08408-1].