Observation of Unusual Surface Ordering in a UniaxialSm−APhase Formed by a Highly Biaxial Compound

Abstract

We have studied one banana-shaped compound using null-transmission ellipsometry. By studying free-standing films of various thicknesses we confirm that this compound exhibits the $\mathrm{Sm}-A$ phase. This is the first banana-shaped compound with a relatively small bend angle ( $\sim 140°$) in which a uniaxial phase has been observed. At the lower temperature end of the $\mathrm{Sm}-A$ phase we observe unusual ordering at the surface of the film.