Smectic A herringbone patternsKralj, Samo (Avtor) Lacaze, Emmanuelle (Avtor) Cordoyiannis, George (Avtor) Kutnjak, Zdravko (Avtor) liquid crystalspatternsstructural transitionsTwo qualitatively different SmA structures exhibiting herringbone-type layer patterns, to which we refer as the Defectless Smectic Herringbone (DSH) and the Dislocation Decorated Smectic Herringbone (DDSH) pattern are studied by a Landau-de Gennes-Ginzburg mesoscopic approach. Liquid crystal structures are described in terms of a nematic director field and a smectic complex order parameter. It is demonstrated that, in the proximity of the N-SmA phase transition, a melting of smectic layers could be realised even for relatively weakly-tilted smectic layers in DSH patterns (i.e. θt ≈ 100) for type I Sm4 phase. The width of melted region could be relatively large with respect to bulk values of the smectic characteristic lengths. In addition, a critical value of θt is determined at which a DDSH pattern is expected to appear.20142017-06-30 09:21:42Članek v reviji66532sl