NEW APPROXIMATE FORMULAS FOR THE RETARDATION FACTORS OF NEMATIC LIQUID-CRYSTALS WITH SIMPLE UNIAXIAL ANISOTROPY

Simple formulae which yield a close approximation to the exact analyti c solution for the longitudinal and transverse relaxation times T para llel to and T perpendicular to of the components of the dipole moment of a nematic liquid crystal with simple uniaxial anisotropy are presen ted. The new formula for T parallel to yields a substantial correction to the Meier-Saupe formula [1966, Molec. Crystals, 1, 515]. It appear s that both the longitudinal and transverse relaxation processes may b e accurately described by a single Debye type relaxation mechanism wit h relaxation times T parallel to and T perpendicular to.