Reexamination of the Helfrich-Hurault effect in smectic-$A$ liquid crystals

The Helfrich-Hurault effect is a phase transition that occurs in samples of cholesteric or smectic liquid crystals subject to external electric or magnetic fields. In this paper we analyze the Helfrich-Hurault effect of smectic-$A$ liquid crystals in an electrostatic field taking into account the complete electromechanical coupling. A comparison is made with the results already obtained for the partially coupled case where one takes into account only the effect of the field on the crystal configuration and considering that field unaffected.

Figure 1

Ratio between the calculated electric field $E_{\mathit{cr}}$ and $E_{\mathit{magn}}$ keeping constant ${\epsilon }_a=-1$.

Figure 2

Calculated ratio between ${\eta }_{\mathit{cr}}$ and ${\eta }_{\mathit{magn}}$ with ${\epsilon }_a=-1$ constant.