Frustrated structure of an anticlinic-like smectic-C phase

• Type: Article in International Scientific Journal
• Date: 2006

Authors

Sebastiao, PJ (Author) Other; Carvalho, PS (Author) FCUP; Chaves, MR (Author) Other; Nguyen, HT (Author) Other; Ribeiro, AC (Author) Other

Journal

Title: European Physical Journal E

Vol. 20

Pages: 55-61

ISSN: 1292-8941

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 5 Citations

Scopus - 5 Citations

Scientific classification

FOS: Engineering and technology > Materials engineering

Other information

Authenticus ID: P-004-KXN

DOI: 10.1140/epje/i2005-10119-2

Abstract (EN): We present a polarising optical microscopy study of the low-temperature anticlinic-like tilted mesophase of the liquid-crystal compound octylphenyl-2-chloro-4-(p-cyano-benzoyloxy) (DB8Cl). This mesophase has been described as a bilayer smectic structure in which the molecules within each layer are organised in an anticlinic way. The optical textures observed in samples with planar orientation show a double stripe pattern, with the lines aligned parallel to the rubbing direction, characteristic of a double periodic modulation of the refractive index of the material. The long-period modulation is temperature dependent and disappears for thin sample cells (< 5 mu m). The short-period modulation is nearly independent of the thickness of the cells. The experimental results are analysed in terms of a model which considers that there is a special distribution of the principal optical axis which may be in or out of the polariser-analyser plane. The observed periodic variation of the principal optical axis could not be interpreted in terms of the original structure proposed for this phase. DB8Cl presents a structure formed by dimers that can be viewed as flexible bent-core-like molecules, showing similarities with phases found in banana-like systems, but exhibiting a much more complex structure.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7