Disruption of surface-induced smectic order by periodic surface corrugations

A Fréedericksz transition measurement is reported for a liquid crystal cell composed of surfactant-coated substrates. One substrate was locally scribed with the stylus of an atomic force microscope to create a nanoscopic grooved structure. The Fréedericksz threshold voltage was found to be smaller in the scribed region than in the unscribed region, indicating that the corrugated surface disrupts surface-induced smectic order, and that the effect grows toward the nematic–smectic-$A$ transition temperature $T_{\mathrm{NA}}$ in conjunction with the smectic correlation length.