1A16 Analysis of intralayer structure of bent-shaped dimer liquid crystals by X-ray microdiffraction

Abstract

Layer structure of bent-shaped achiral dimers, having two rod-like mesogens connected with a methylene spacer, designated as m (O) AMnAM (O) m, was investigated using x-ray microdiffraction. In this paper, we will present the result of intralayer moelcular orientation in each dimer by x-ray microdiffraction. In the low birefringence domain of 8OAM5AMO8, in which only (002) layer diffraction was observed, four halo diffuse peaks appear at wide angle, while halo changes to two peaks parallel to the layer in the high birefringence domain where (101) peaks are observed. This change is consistent with the previuos results of molecular reorientation due to dielectric anisotropy. Similar results are observed in mOAM5AMOm (m=10, 12 and 16), which suggest that the smectic phase in 16OAM5AMO16 also has frustrated structure. In the high field application of 16OAM5AMO16, molecular tilt was also observed.