Simultaneous photoacoustic measurements of specific heat and thermal conductivity critical behaviour at a smectic A-nematic phase transition

Simultaneous measurements of the thermal conductivity and specific heat at the smectic A-nematic phase transition in 4-n-octyl-4'-cyanobiphenyl (8CB) have been carried out with the photoacoustic technique. A critical increase in the thermal conductivity is reported. A critical decrease in the thermal diffusivity data confirms that the transition in 8CB is fluctuation dominated as also shown by the critical behaviour of the specific heat.