FIELD-INDUCED BIAXIALITY IN SMA PHASE OF A LIQUID-CRYSTAL EXHIBITING ELECTROCLINIC EFFECT

The field-induced biaxiality of a liquid crystal which exhibits a strong electroclinic effect in the SmA phase has been detected by means of transitional dielectric constant measurement. The biaxiality in dielectric constants increases along with the molecular tilt as the applied voltage increases and as the temperature approaches the SmA-SmC* transition point. These experimental findings are explained qualitatively in terms of a Landau-type free energy theory by adding a term which represents the effect of the induced dielectric biaxiality.