BEHAVIOR OF THE ELECTROCLINIC EFFECT IN A HOMOLOGOUS SERIES OF FERROELECTRIC LIQUID-CRYSTALS

The electroclinic effect, a kind of inverse piezoelectric effect, is studied in the smectic A phase of several homologous liquid crystal compounds. The induced tilt/applied field ratio theta/E is found to increase with increasing length of the alkyl chain whereas the coupling constant k = P-theta/theta-between induced tilt and induced polarization decreases with increasing chain length. The measurements allow the determination of the tilt controlling susceptibility coefficient of the smectic A phase, which is found to decrease considerably with increasing alkyl chain length.