Doubly periodic instability pattern in a smectic-A liquid crystal
2013 (English)In: Physical Review E. Statistical, Nonlinear, and Soft Matter Physics, ISSN 1539-3755, Vol. 87, no 5, 050501- p.Article in journal (Refereed) Published
We report the observation of a doubly periodic surface defect pattern in the liquid crystal 8CB, formed during the nematic-smectic-A phase transition. The pattern results from the antagonistic alignment of the 8CB molecules, which is homeotropic at the surface and planar in the bulk of the sample cell. Within the continuum Landau-de Gennes theory of smectic liquid crystals, we find that the long period (approximate to 10 mu m) of the pattern is given by the balance between the surface anchoring and the elastic energy of curvature wall defects. The short period (approximate to 10 mu m) we attribute to a saddle-splay distortion, leading to a nonzero Gaussian curvature and causing the curvature walls to break up.
Place, publisher, year, edition, pages
American Physical Society , 2013. Vol. 87, no 5, 050501- p.
IdentifiersURN: urn:nbn:se:su:diva-91526DOI: 10.1103/PhysRevE.87.050501ISI: 000319118100001OAI: oai:DiVA.org:su-91526DiVA: diva2:634693
FunderEU, FP7, Seventh Framework Programme, EuroMagnet II; 228043