2005/07/01 by M. Kleman, C. Meyer, Yu. A. Nastishin · 1 citation
Engineering · Materials Science · Physics and Astronomy · #Advanced Materials and Mechanics #Boundary (topology) #Conic section #Ellipse #Hyperbola #Ideal (ethics) #Imperfect #Liquid Crystal Research Advancements #Liquid crystal #Nonlinear Photonic Systems #Phase transition #cond-mat.soft
paper · pdf · doi:10.1080/14786430600724496
19 pages, 18 figures
arxiv created 2005/07/01 · openalex publication_date 2006/05/09 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
It is usual to think of focal conic domains (FCDs) as perfect geometric constructions in which the layers are folded into Dupin cyclides about an ellipse and a hyperbola that are conjugate. This ideal picture is often far from reality. We have investigated in detail the FCDs in several materials that have a transition from a smectic A (SmA) to a nematic phase (N). The ellipse and the hyperbola are seldom perfect, and the FCD textures also suffer large transformations (in shape and/or in nature) when approaching the transition to the nematic phase, or appear imperfect on cooling from the nematic phase. We interpret these imperfections as due to the interaction of FCDs with dislocations. We analyze theoretically the general principles subtending the interaction mechanisms between FCDs and finite Burgers vector dislocations, namely the formation of kinks on disclinations, to which dislocations are attached, and we present models relating to some experimental results. Whereas the principles of the interactions are very general, their realizations can differ widely in function of the boundary conditions.