Hexatic antiferroelectric SmIA*phase in MHPOCBC

We investigated a novel antiferroelectric phase appearing below the SmCA* phase. The electrooptic measurement in this phase clearly manifests the tristable switching, which is the same as that in the SmCA* phase. The intralayer correlation obtained by X-ray diffraction suggests that the phase under consideration must be of the higher order smectic phases, such as SmBhex, SmI and SmF. In addition, the interlayer correlation measurement by X-ray diffraction shows a similar behavior to that in the hexatic SmI phase. Thus, we conclude that this phase is the antiferroelectric hexatic phase, SmIA*.