Thermal conductivity of the nematic liquid crystal 4-n-pentyl-4’-cyanobiphenyl

We report experimental results for the thermal conductivities of 4-n-pentyl-4'-cyanobiphenyl (5CB) for 19 ^∘{}CT48 ^∘{}C. For TTNI=35.17 ^∘{}C this substance is a nematic liquid crystal, where TNI is the nematic-isotropic transition temperature. The conductivities were determined by measuring the temperature difference across a horizontal layer of the fluid heated from below in magnetic fields either parallel or perpendicular to the heat current. The field magnitude was much larger than the Fr\'eedericksz field. For TTNI, this yielded monodomain samples with the director oriented parallel to the field, and thus the conductivities λ_∥ and λ_⊥ with the director parallel and perpendicular to the heat current, respectively.