Ferroelectric and antiferroelectric modes in a new chiral thiobenzoate liquid crystal

• Tipo: Artigo em Revista Científica Internacional
• Data: 1996

Autores

Carvalho, PS (Autor) FCUP; Chaves, MR (Autor) FCUP; Destrade, C (Autor) Outra; Nguyen, HT (Autor) Outra; Glogarova, M (Autor) Outra

Revista

Título: Liquid Crystals

Vol. 21

Páginas: 31-37

ISSN: 0267-8292

Editora: Taylor & Francis

Indexação

ISI Web of Knowledge - 19 Citações

Scopus - 24 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia dos materiais

Outras Informações

ID Authenticus: P-001-E2Z

DOI: 10.1080/02678299608033793

Abstract (EN): This work concerns the dielectric relaxation study of a new compound containing a thiobenzoate group with a fluoro substituent, which presents a sequence of antiferro-, ferri-, ferroelectric and S-C alpha* phases. The polar character of these phases was confirmed by optical hysteresis loops. Three modes with a nearly monodispersive behaviour were identified: the soft mode, the Goldstone mode and a non-collective azimuthal mode. The soft mode softens above the S-A-S-C alpha* transition and triggers another mode within the S-C alpha* phase. Moreover, a collective anti-phase azimuthal mode appears and may be the origin of the onset of the antiferroelectric S-CA* phase. A strong influence of surface interactions on the thermal hysteresis and on the dielectric constant was evident in this work.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 7