Formation of disclinations line near a free nematic interface

We have studied the nucleation and the physical properties of a -1/2 wedge disclination line near the free surface of a confined nematic liquid crystal. The position of the disclination line has been related to the material parameters (elastic constants, anchoring energy, and favored anchoring angle...

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Detalhes bibliográficos
Autores: Ignés i Mullol, Jordi, Baudry, Jean, Lejcek, Lubor, Oswald, Patrick
Formato: artículo
Estado:Versión publicada
Fecha de publicación:1999
País:España
Recursos:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/18911
Acesso em linha:https://hdl.handle.net/2445/18911
Access Level:acceso abierto
Palavra-chave:Estructura cristal·lina (Sòlids)
Cristal·lografia
Structure of solids and liquids
Crystallography
Descrição
Resumo:We have studied the nucleation and the physical properties of a -1/2 wedge disclination line near the free surface of a confined nematic liquid crystal. The position of the disclination line has been related to the material parameters (elastic constants, anchoring energy, and favored anchoring angle of the molecules at the free surface). The use of a planar model for the structure of the director field (whose predictions have been contrasted to those of a fully three-dimensional model) has allowed us to relate the experimentally observed position of the disclination line to the relevant properties of the liquid crystals. In particular, we have been able to observe the collapse of the disclination line due to a temperature-induced anchoring-angle transition, which has allowed us to rule out the presence of a real disclination line near the nematic/isotropic front in directional growth experiments.