Raman studies in SmCFI* phases

• Tipo: Artigo em Revista Científica Internacional
• Data: 2004

Autores

Carvalho, PS (Autor) FCUP; Yuzyuk, YI (Autor) Outra; Almeida, A (Autor) FCUP; Chaves, MR (Autor) Outra; Pinto, F (Autor) Outra; Cruz, CD (Autor) Outra; Nguyen, HT (Autor) Outra

Revista

Título: Liquid Crystals

Vol. 31

Páginas: 727-732

ISSN: 0267-8292

Editora: Taylor & Francis

Indexação

ISI Web of Knowledge - 1 Citação

Scopus - 1 Citação

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia dos materiais

Outras Informações

ID Authenticus: P-000-ANB

DOI: 10.1080/02678290410001681573

Abstract (EN): The study of the Raman intensity of the 'breathing' mode of the benzene rings as a function of the temperature in smectic phases revealed strong anomalies of the intensities I-ZZ and I-YY in SmCFI2* and SmCFI1 * phases, as well as an important shift of the principal optical direction with respect to other smectic phases. The analysis of these results provided evidence for significant structural changes at the SmC*-SmCFI * and SmCFI *-SmCA * phase transitions, because the molecules can no longer be treated as cylindrical rods. No anomalies in the tilt angle were found. Experimental results suggest a relationship between the deviation of the optical axis and the particular structure of the SmCFI * phases. The deviation of I-ZZ maxima as a function of the rotation angle Psi and the behaviour evident under an electric field in SmCFI * and SmCA * phases clearly excludes the coexistence of SmCA * and SmC* local domains in SmCFI * phases.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 6