X-ray studies of layer structure and needle defects in anti-parallel aligned SSFLC devices with medium pre-tilt

Abstract

X-ray diffraction has been used to investigate the structure of ferroelectric Smectic C* (SmC*) devices with anti-parallel orientation of the alignment layers. The layer structure during cooling from the Smectic A (SmA) phase has been determined for three different surface pre-tilts. The results are presented as two-dimensional layer normal distributions that show in detail the changes in layer orientation as a function of temperature. For low and medium pre-tilt surfaces a transformation from a uniformly tilted layer in the Sm A to a chevron in the Sm C was observed in monodomain regions. These surfaces also tended to show needle defects in the Sm C and their layer structure is discussed.

Keywords:

• X-ray diffraction
• smectic C
• layer structure
• chevron
• ferroelectric liquid crystal