The dielectric properties of 4-pentyloxy-and 4-heptyloxy-4'-cyanobiphenyls and their eutectic mixture

The temperature dependences of static permittivity were obtained for the nematic and isotropic liquid phases of 4-pentyloxy- and 4-heptyloxy-4'-cyanobiphenyls and their eutectic mixture. The theory of anisotropic dielectrics was used to calculate the longitudinal and transverse effective dipole moment components and the Kirkwood dipole-dipole correlation factor. The role played by dipole-dipole association in the formation of the so-called "secondary" low-temperature nematic phase was analyzed.