Critical behavior of thermal parameters at the smectic-A -hexatic-B and smectic-A -smectic-C phase transitions in liquid crystals

An analysis of the thermal conductivity, thermal diffusivity, and specific heat at the smectic-A-hexatic-C (AC), and the smectic-A-hexatic-B (AB) phase transitions of liquid crystals, was presented. The experimental setup used consisted of a standard photopyroelectric working in its back detection and configuration. The sample was sandwiched between the titanium coated glass cover and the transparent pyroelectric sensor. A nonsingular behavior was exhibited by thermal conductivity at both transitions. Results show that the nature of the transition, in several cases, can be affected by the sample thermal history due to the presence of strain annealing phenomena.