X-Ray Study of the Layer Structure in a High Pre-Tilt, Anti-Parallel Aligned Ferroelectric Liquid Crystal

Abstract

X-ray diffraction has been used to investigate the layer structure of a ferroelectric liquid crystal device as a function of temperature. Obliquely evaporated silicon monoxide alignment layers arranged anti-parallel to each other were used to align a 2μ sample of racemic SCE13. In the smectic A phase, the cell formed a uniform tilted layer with a tilt angle in good agreement with the 25° pre-tilt of the SiO. Below the transition to Smectic C there was evidence for a highly asymmetric chevron with layers oriented away from the preferred alignment plane, together with domains of uniformly tilted layers. Further cooling to 30°C caused the chevron structure to disappear, until only the uniformly tilted layer remained.

Key Words:

• X-rays
• layer structure
• smectic C
• ferroelectric liquid crystal