Ellipsometric study of freely suspended smectic films of a partially fluorinated compound

High-resolution ellipsometric studies have been conducted on freely suspended films of a chiral, partially perfluorinated liquid-crystal compound near its smectic-A–smectic-C transition. The surface-enhanced transition is unusually close to the bulk transition temperature. Moreover, in the ferroelectric smectic-C phase an unexpected tilt direction inversion with respect to the direction of an applied electric field is found in films thinner than about 20 layers whereas it does not occur in thick films