Chevron layer structures in surface stabilized ferroelectric liquid crystal (SSFLC) cells filled with a material which exhibits the chiral nematic to smetic C* phase transition

Conference · Sun Jan 01 04:00:00 EST 1989

DOI:https://doi.org/10.1080/00150199108014067· OSTI ID:5846389

Rieker, T P; Clark, N A; Safinya, C R

In this paper we report on the layer structure in Surface Stabilized Ferroelectric Liquid Crystal (SSFLC) electro-optic cells, adopted by a compound which exhibit the smectic C* (SC*) to chiral nematic (N*) phase transition. This class of compounds is unique in that the SC* layers form directly from the N* phase. These materials demonstrate a large tilt (/Theta/) of the director (/cflx n/) from the layer normal (/cflx z//prime/) immediately upon cooling into the SC* phase. Recent high resolution x-ray experiments have demonstrated the presence of a chevron layer structure of tilted layers in compounds which exhibit the smectic A (SA) to SC* and the N*-SC* phase transitions, and also in a compound which has a very broad smectic A Phase. Chevron formation in smectic samples is a result of the layers anchoring normal or nearly normal to the bounding plates and subsequent layer contraction in the absence of dislocations. Patel and Goodby have demonstrated that compounds which exhibit the N*-SC* phase transition in the SSFLC geometry can be aligned by the application of an electric field across a cell with a buffed polymer surface treatment. With this method two domains of smectic layers form at large angles to the buffing direction normal. This is a consequence of the system simultaneously satisfying the imposed alignment direction, the large director tilt angle /Theta/, surface stabilization and the alignment of the polarization (P) along E. 9 refs., 5 figs.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5846389
• Report Number(s): LA-UR-89-2840; CONF-8906207-1; ON: DE89016985
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
CHIRALITY
CRYSTAL STRUCTURE
CRYSTALS
ELECTRIC FIELDS
FERROELECTRIC MATERIALS
FLUIDS
LAYERS
LIQUID CRYSTALS
LIQUIDS
PARTICLE PROPERTIES
PHASE TRANSFORMATIONS
POLARIZATION
SCATTERING
TEMPERATURE DEPENDENCE