Influence of substrate microrelief on the Fréedericksz transition in a thin nematic cell

An effect of substrate surface regular wavy microrelief on the Freedericksz transition in a thin homeotropically aligned nematic cell near the smectic-$A$–nematic second-order transition temperature is theoretically investigated. It is shown that because of the suppression of an interfacial smectic-$A$ structure, the Fréedericksz critical field for the cell with substrates having a sufficiently sharp microrelief should be significantly lower than that for the cell of the same thickness, but with perfectly flat substrates.