Combined X-Ray and Fully Leaky Guided Mode Studies of the Smectic Layer and Optic Tensor Configuration in a Ferroelectric Liquid-Crystal Cell

Symmetries and alignment of biaxial nematic liquid crystals

“…These tilted and layered systems exhibit C 2h phase biaxiality, with the twofold axis perpendicular to the tilt plane. Tilt-angle measurements are known to give appreciable, and temperature dependent, differences between the tilt-angle values obtained from optical, X-ray, NMR etc [38][39][40][41][42][43][44] methods on the same SmC compound, as well as differences between the mesogenic-core and pendant alkyl chain tilt-angles. [41][42][43][44] Furthermore, different tilt angles, and therefore distinct PAFs, for different properties of the same compound are obtained as direct theoretical results from molecular models in which internal flexibility together with the characteristic aliphatic-aromatic molecular composition of the SmC compounds are explicitly taken into account.…”

“…Tilt-angle measurements are known to give appreciable, and temperature dependent, differences between the tilt-angle values obtained from optical, X-ray, NMR etc [38][39][40][41][42][43][44] methods on the same SmC compound, as well as differences between the mesogenic-core and pendant alkyl chain tilt-angles. [41][42][43][44] Furthermore, different tilt angles, and therefore distinct PAFs, for different properties of the same compound are obtained as direct theoretical results from molecular models in which internal flexibility together with the characteristic aliphatic-aromatic molecular composition of the SmC compounds are explicitly taken into account. [45][46][47] In the present context, these differences in the tilt angles obviously correspond to the shift-angles among the transverse principal axes associated with anisotropic properties of the C 2h biaxial nematic medium.…”

Guided mode studies of liquid crystal layers

“…However, recently some improvements [21] have been introduced to the fully-leaky geometry, in which two refinements to the original technique have been made to make it much more useful. Firstly, the full sets of both transmission, T, and studies have been undertaken to explore the smectic layer and the optic tensor configuration in a ferroelectric liquid crystal cell [75]. All of this work, using the guided mode technique to explore conventional commercial-like cells, paves the way for detailed exploration of the behaviour of such cells under various conditions and also allows dynamic studies.…”