Raman studies in SmCFI* phases

• Type: Article in International Scientific Journal
• Date: 2004

Authors

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

Journal

Title: Liquid Crystals

Vol. 31

Pages: 727-732

ISSN: 0267-8292

Publisher: Taylor & Francis

Indexing

ISI Web of Knowledge - 1 Citation

Scopus - 1 Citation

Scientific classification

FOS: Engineering and technology > Materials engineering

Other information

Authenticus ID: 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6