Focal Conics Domains in Smectics

摘要: A lamellar phase constituted by equidistant flat layers presents typical structural defects called Focal Conic Domains (FCD), in which the (Dupin cyclides) are folded around two conjugated lines. The aim of this paper is to give a complete review geometrical and energetical aspects FCDs. Also, some textures will be described. After brief historical recall discovery FCD’s G. Friedel, we describe conformation FCD’s. We consider different fundamental types phase, pointing out topological differences between them. An analytical description Dupin cyclide made, particular introduce their curvature, starting point energy’ s calculation FCD. with number physical situations.