Vsu. Fazio et L. Komitov, Alignment transition in a nematic liquid crystal due to field-induced breaking of anchoring, EUROPH LETT, 46(1), 1999, pp. 38-42
We report on the alignment transition of a nematic liquid crystal from init
ially homeotropic to quasi-planar due to field-induced anchoring breaking.
The initial homeotropic alignment is achieved by Langmuir-Blodgett monolaye
rs. In this geometry the anchoring strength can be evaluated by the Frederi
ks transition technique. Applying an electric field above a certain thresho
ld provokes turbulent states denoted DSM1 and DSM2. While DSM1 does not aff
ect the anchoring, DSM2 breaks the coupling between the surface and the liq
uid crystal: switching off the field from a DSM2 state does not immediately
restore the homeotropic alignment. Instead, we obtain a quasi-planar metas
table alignment. The cell thickness dependence for the transition is relate
d to the cell thickness dependence of the anchoring strength.