Abstract
Experimental and theoretical studies of a smectic-–hexatic- transition in freely suspended films of thickness of the -pentyl--pentanoyloxy-biphenyl-4-carboxylate (54COOBC) compound are presented. X-ray investigations revealed a discontinuous first-order transition into the hexatic phase. The temperature region of two-phase coexistence near the phase transition point diminishes with decreasing film thickness. The width of this temperature region as a function of the film thickness was derived on the basis of a Landau mean-field theory in the vicinity of a tricritical point (TCP). Close to TCP the surface hexatic- order penetrates anomalously deep into the film interior.
- Received 1 June 2018
DOI:https://doi.org/10.1103/PhysRevE.98.052703
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