Pretransitional Behavior of 8–12 CB

Abstract

The magnetic birefringence in the isotropic phase vs temperature for the liquid crystals alkyl cyanobiphenyls (C _n H_2n+1 CN), n = 8–12, has been measured. The inverse of the Cotton-Mouton coefficient, R, vs temperature T were plotted. The shape and the influence of the smectic phase on the “bending down” in the R vs T curve near the clearing point T_c are discussed. The so-called “odd-even effect” are observed. In our experiments, in 9 CB and 11 CB, the “inflection” or “saturation” in the “bending down” region mentioned in the work of Coles and Strazielle, and Pouligny et al, respectively, are not observed.