Showing papers by "Samo Kralj published in 2000"
TL;DR: The influence of the surface treatment on the Sm-A-N phase transition of the 8CB (octylcyanobiphenyl) liquid crystal confined to controlled pore glass (CPG) matrices is studied and a theoretical description based on the Landau-de Gennes type approach is developed to explain the experimental data.
Abstract: The influence of the surface treatment on the Sm-A-N phase transition of the 8CB (octylcyanobiphenyl) liquid crystal confined to controlled pore glass (CPG) matrices is studied. The characteristic linear size of voids in the chosen CPG matrix is 0.2 mm. The voids' surface was either nontreated or silane treated enforcing tangential or homeotropic anchoring, respectively. In both cases the x-ray measurements reveal a qualitative change of the temperature dependence of the smectic order-parameter correlation length in comparison to the bulk sample. In addition, the apparent smectic pretransitional ordering is observed for the silane-treated sample. A theoretical description based on the Landau-de Gennes type approach is developed to explain the experimental data. The surface positional anchoring strength of the silane-treated sample is estimated to be of the order of 10(-4) J/m(2) and at least 100 times weaker for the nontreated case.
15 citations
TL;DR: In this article, an x-ray scattering study of the smectic A ordering of the liquid crystal 8CB (octylcyanobiphenyl) confined to a control porous glass with a typical void radius R = 0.2 µm was performed.
Abstract: We performed an x-ray scattering study of the smectic A (SmA) ordering of the liquid crystal 8CB (octylcyanobiphenyl) confined to a control porous glass with a typical void radius R = 0.2 µm. The voids were either nontreated or covered with silane. The results reveal a strong influence of spatial restriction and surface treatment on the temperature evolution of smectic ordering. The observations are qualitatively reproduced using the Landau-Ginsburg approach.
7 citations
TL;DR: In this article, surface driven formation of a lattice of edge dislocations in the SmA phase in the semi-infinite geometry using Landau-Ginsburg phenomenological approach was studied.
Abstract: We study surface driven formation of a lattice of edge dislocations in the SmA phase in the semiinfinite geometry using Landau-Ginsburg phenomenological approach and estimate the conditions where the dislocation structure is stable over the tilted structure and the threshold for the formation of an edge dislocation on increasing the surface positional anchoring strength W p . The detail structure of an edge dislocation is numerically studied as a function of W p .