X-ray investigation of the smecticAreentrant nematic transition under pressure (CBOOA)

The authors present the first x-ray measurement of the liquid crystal smectic $A$ phase layer spacing at high pressure. It is found that at relatively high temperatures, when the smectic $A$ phase is compressed toward the reentrant nematic phase, there is no change in the layer spacing. On the other hand, at lower temperatures, where the smectic $A$ phase is being compressed toward the stable solid phase, the layer spacing decreases. A systematic increase in the layer spacing as a function of time is also noted.