Temperature dependence of the smectic layer structures was studied by high resolution X-ray diffraction analysis. The investigation was based on two different alignment SSFLC cells. The effect of layer spacing changes in the SmA phase on defects seen in the SmC phase of the devices is investigated. It is shown that when considering a defect free SmC* texture, the layer spacing changes in the SmA phase are more significant than changes in the SmC phase. An explanation is also proposed.
It is generally considered that the symmetric chevron is the lowest energy layer structure. However, we show that for SSFLC devices with a twisted director configuration that an asymmetric layer structure may be preferred. For typical cell parameters, we find that the lowest elastic energy condition is for the apex located at about 1/3 of the cell thickness. In this paper, the effect of cell and material parameters, as well as experimental data will be presented.