| Revista: | Brazilian journal of physics |
| Base de datos: | PERIÓDICA |
| Número de sistema: | 000146844 |
| ISSN: | 0103-9733 |
| Autores: | Mesquita, Oscar Nassif de1 |
| Instituciones: | 1Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais. Brasil |
| Año: | 1998 |
| Periodo: | Dic |
| Volumen: | 28 |
| Número: | 4 |
| Paginación: | 257-266 |
| País: | Brasil |
| Idioma: | Inglés |
| Tipo de documento: | Artículo |
| Enfoque: | Analítico |
| Resumen en inglés | Liquid crystals have been very fruitful systems to study equilibrium phase transitions. Recently, they have become an important system to study dynamics of first-order phase transitions. The moving nonequilibrium nematic-isotropic interface is a model system to study growth of stable states into metastable states and displays a myriad of dynamical instabilities that, far from equilibrium, drive the system to a scenario of spatio-temporal chaos. We present a mean-field theory for the time evolution of a planar nonequilibrium nematic-isotropic interface for pure liquid crystals using a time dependent Ginzburg-Landau equation, which is one of the simplest approaches to dissipative dynamics. We obtain a theoretical expression for the growth kinetics of the nematic phase into a metastable isotropic phase and compare it with our experimental results. In a directional solidification arrangement we study instabilities of the nematic-isotropic interface of the liquid crystal 8CB doped with water and hexachloroethane. The observed instabilities are similar to cellular instabilities that appear during growth of crystal-melt interfaces of binary mixtures. We then compare our results with known theories of morphological instabilities during crystal growth |
| Disciplinas: | Física y astronomía |
| Palabras clave: | Física de materia condensada, Termodinámica y física estadística, Cristales líquidos, Inestabilidad, Termodinámica, Crecimiento de cristales, Transición de fase, Ecuaciones de Ginzburg-Landau |
| Keyword: | Physics and astronomy, Condensed matter physics, Thermodynamics and statistical physics, Liquid crystals, Instability, Thermodynamics, Crystal growth, Phase transition, Ginzburg-Landau equations |
| Texto completo: | Texto completo (Ver HTML) |
