The study of phase transition for new banana-shaped liquid crystals

초록

We have studied the electro-optical characteristics to look for molecular structure by using several different techniques for new banana-shaped liquid crystals. Based on the similarities to recently observed fluoro-containing materials (Switching involves layer structure rearrangement, increasing threshold with increasing temperatures) for one of our samples attached hydrogen on a benzene ring(HC) , we assume that the phase C has a triclinic symmetry corresponding to the double tilted SmCG phase. The observation that the polarization peak appears at lower fields (Eo~15V/um) than the amplitude of the threshold (Eth) can be explained assuming a field induced SmCG - SmCP(or SmAP) transition at Eth. Based on the textures, the mesophase of other samples attached chlorine and fluorine (CC and FC , respectively) seem to be a tilted columnar phase. We are in progress to finalize the molecular structures by x-ray measurements.