Evidence for a Smectic-A—Nematic Tricritical Point: Binary Mixtures

Abstract

Differential scanning calorimetry measurements of the smectic-$A$—nematic latent heat of transition in binary mixtures of ${\mathrm{C}}_8$ ${\mathrm{H}}_{17}$O-${\mathrm{C}}_6$ ${\mathrm{H}}_4$-CHN-${\mathrm{C}}_6$ ${\mathrm{H}}_4$-${\mathrm{C}}_3$ ${\mathrm{H}}_7$ (8O.3) and ${\mathrm{C}}_2$ ${\mathrm{H}}_5$O-${\mathrm{C}}_6$ ${\mathrm{H}}_4$-CHN-${\mathrm{C}}_6$ ${\mathrm{H}}_4$-${\mathrm{C}}_3$ ${\mathrm{H}}_7$ (2O.3) strongly suggest the existence of a tricritical point at approximately 70 mole% 8O.3.