THERMAL-CONDUCTIVITY AND THERMAL-DIFFUSIVITY ANISOTROPY IN A LIQUID-CRYSTAL

Thermal conductivity (k) and thermal diffusivity (D) of the 9CB liquid crystal have been simultaneously determined by a photopyroelectric (P PE) technique in the temperature range from 308 K to 332 K where two d ifferent phase transitions occur. The measurements have been performed on oriented samples and the k and D anisotropy has been studied. The behaviour of the macroscopic order parameter vs. temperature has been determined and the order of the phase transitions checked.