Stability and phase transitions of single-molecular-layer free-standing liquid-crystal films

Abstract

We have successfully prepared stable one-layer films of 54COOBC $[n$-pentyl-${4}^{\ensuremath{'}}\ensuremath{-}n$-pentanoyloxy biphenyl-4-carboxylate] in a small film hole $(\ensuremath{\approx}0.7$ mm in diameter) and conducted high-resolution optical reflectance measurements near the smectic-$A$--hexatic-$B$ transition. The stability of these films is contrary to experiences with all other compounds and also to heuristic understanding. We propose a modification to such understanding. Within the resolution of our measurements, data are in good agreement with those of two-layer films. The result gives a confirmation of two-dimensional behavior of two-layer films.