Banca de DEFESA: DEBORA CRISTINA SILVA DE MELO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : DEBORA CRISTINA SILVA DE MELO
DATE: 08/10/2021
TIME: 13:30
LOCAL: Instituto de Física (remotamente)
TITLE:

Electrical field effects on liquid-crystalline systems involving the smectic-C phase

KEY WORDS:

Liquid crystlas, Phase transitions, Microscopic models, mean-field theory

PAGES: 98
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUMMARY:

In the present work, we investigate the phase transitions in liquid-crystalline systems involving the smectic-C phase under the effect of an external electric field. Initially, a review of the theoretical model of Maier-Saupe, which describes the nematic-isotropic phase transition was performed, where we determine the behavior of the order parameter, which abruptly goes to zero at the transition temperature. We then approach the McMillan model, which is an extension of the Maier-Saupe model, including the smecticA-nematic transition in our study. With this model we determine the behavior of the order parameters as a function of temperature and reproduce the phases diagrams. In addition, to these two well-known models, we have included in the work a brief review of the model developed by Govind and Madhusudana, which describes the smectic-C -smectic-A phase transition. This model motivated us to further study the smectic-C phase, which made us propose a new theoretical model on the liquid crystalline phase in question. With our model, it was possible to determine the properties of the system, which allowed us a more complete analysis and description of the phase transitions involving the smectic-C phase, in addition to using a smaller amount of descriptive model parameters. Finally, we analyze the effect of an external electric field on phase transitions involving the Sm-C phase, studying the changes in the thermodynamic and statistical properties of the system under such effect.

BANKING MEMBERS:
Externo ao Programa - 2570322 - ASKERY ALEXANDRE CANABARRO BARBOSA DA SILVA
Interno - 1366820 - IRAM MARCELO GLERIA
Presidente - 2458049 - ITALO MARCOS NUNES DE OLIVEIRA
Interna - 2621034 - MARIA SOCORRO SEIXAS PEREIRA