Structural order and entropy in Schiff base mesogens, 2MBAC and 4MBAC, exhibiting orthogonal smectic phases (SmA, HexB, CrB)

Abstract

Two Schiff base mesogens, 2MBAC and 4MBAC, exhibit four liquid crystal phases, N, SmA, and two types of SmB phases, on cooling. Heat capacities of those compounds were measured by adiabatic calorimetry. Their temperature dependences of entropy were estimated from the heat capacities. We discuss the relation between the entropy and the smectic order parameter estimated from x-ray diffraction in the two compounds.