Reentrant nematic and smectic A phases : the dielectric approach

Abstract
We report the first dielectric investigations of the double reentrant phenomenon N-SA-N-SA. These measurements are in good agreement with an earlier X-Ray analysis. Both smectic A phases present very different behaviours in their dielectric constants as well as in their parallel relaxation times. In addition, the reentrant nematic can be seen as the simultaneous presence of two types of smectic short range order, one characterizing the low temperature SA and the other the high temperature smectic A