Efeito Hall térmico anômalo em cristais líquidos de núcleo encurvado

Detalhes bibliográficos
Ano de defesa: 2021
Autor(a) principal: SOUZA, Lidiane Maria de lattes
Orientador(a): PEREIRA, Erms Rodrigues
Banca de defesa: BARBOSA, Anderson Luiz Rocha e, SENA JÚNIOR, Marcone Isidorio de
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal Rural de Pernambuco
Programa de Pós-Graduação: Programa de Pós-Graduação em Física Aplicada
Departamento: Departamento de Física
País: Brasil
Palavras-chave em Português:
Área do conhecimento CNPq:
Link de acesso: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/9370
Resumo: Sensors have been shown to be of fundamental importance in data collection from a system. They are widely applied in industries around the world and this implies in use of different physical properties. For example, some of these sensors, as the thermal sensors, use different materials that can make it difficult to the mastery of technique. Consequently, the cost increase of your manufacture thus prevents industrialization and marketing. In this work, we predict the occurrence of the anomalous thermal Hall effect in folded core liquid crystals. This is an analogue to the classical Hall effect, and can to be characterized as an emergence of a transverse temperature difference (Hall temperature difference - HTD) in a tape, when heat flows through it, without the application of an external magnetic field. We use the phase theory of bent-core liquid-crystal phases and phase transitions, based on a third-order tensor Tijk. We showed algebraically and computationally, using finite element software, the occurrence of this physical phenomenon. Thus, the HTD values for a micrometer tape, filled with material in the chiral biaxial nematic phase, were obtained with the variation of the tape area and the intensity of the external heat flux. We determine the relationship of these parameters to the HTD. Thus, we identify the anomalous thermal Hall effect in these materials and point this mesophase as a good candidate for the construction of new thermal sensors.