Phase transitions in ferro-electric liquid crystal dobambc by density

Thermal microscopy, differential scanning calorimetry and dilatometric investigations are carried out on the ferroelectric liquid crystal N(p-n-Decyloxybenzylidene) p-amino 2-methylbutyl cinnamate viz., DOBAMBC which exhibits smectic-A, smectic-C* and monotropic Smectic-H phases. The isotropic-smectic-A (IA), smectic-A-Smectic-C* (AC*) and smectic-C*-Smectic-H (C*H) transitions are found to be first order. Detailed study of pre-transitional effects inferred the nucleation growth analogy to IA transition and a clear first order AC* transition in contrast to predicted second order AC transition. The estimated pressure dependence of transition temperatures using the molar volume and enthalpy data are presented.

Keywords:

• ferroelectric liquid crystal
• phase transitions
• nucleation analogy

Notes

Department of Chemistry & Biological Sciences, Oregon Graduate Institute of Science and Technology, Beaverton, Oregon, U.S.A.