Double helical defects in smectic A and smectic A* phases

Autor:	Harrod P. Logbo, Maurice Kleman, B. Briouel, J.-C. Picot, Claire Meyer, Yu. A. Nastishin
Rok vydání:	2010
Předmět:	Crystallography Optics Materials science business.industry Liquid crystal Phase (matter) General Materials Science General Chemistry Ideal (ring theory) Condensed Matter Physics business SMA
Zdroj:	Liquid Crystals. 37:1047-1057
ISSN:	1366-5855 0267-8292
DOI:	10.1080/02678291003782846
Popis:	Double helical (DH and DH*) domains, defects of the smectic A (SmA) phase, have for the first time been studied in the smectic A* (SmA*) phase, composed of chiral molecules. Both left- and right-handed DH*s are found in SmA*s, but not in equal numbers. The majority of the DH*s in the two left-handed cholesterics studied are left-handed, whereas in the SmA phase of non-chiral molecules the DHs are left- and right-handed in equal numbers. DHs and DH*s, which are topologically screw dislocations of giant Burgers vectors, appear to be significantly distorted with respect to a geometrically ideal model. It has been shown that imperfections in the DH*s and DHs are covered by a combination of three types of elementary distortions. The relation between the pitch in DH* and DH and temperature is discussed.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::424969e2453165666fae30b3bcba320c https://doi.org/10.1080/02678291003782846 Zobrazit plný text záznamu