Layer compression modulus measurements near the smectic-hexatic phase transition

Abstract

Layer compression modulus measurements have been conducted in the vicinity of the smectic-C -smectic-I and smectic-C_A -smectic-I_A phase transitions of chiral smectic liquid crystals. Layer compression modulus shows no pretransitional softening near the smectic-C -smectic-I phase transition as expected. Unlike the usual smectic-hexatic phase transition, we observed evident critical softening of layer compression modulus near the smectic-C_A -smectic-I_A phase transition.