A dielectric study of three chiral liquid crystals presenting SmCFI* phases

We have performed a detailed dielectric study of three compounds presenting ferrielectric phases over large temperature intervals. The relaxation proc esses detected in the SmCF1* phases are highly polidispersive. We have repe atedly observed the surface layer mode described by Bourny er al. [1] and a weak ferrielectric mode, whose relaxation frequency is always higher on he ating than on cooling runs. The temperature interval where SmCF1* phases oc cur is apparently independent of cooling/heating rates and of the history o f the sample.