Chiral smectic C subphases induced by mixing a bistereogenic antiferroelectric liquid crystal with a non-chiral liquid crystal
Artikel i vetenskaplig tidskrift, 2005

By mixing a bistereogenic antiferroelectric liquid crystal (AFLC) compound, exhibiting only the SmQ* and SmC a * mesophases, with the achiral N-SmC liquid crystal HOAB we could induce all three AFLC SmC-type subphases, SmC α *, SmC β * and SmC γ *. This seems to be in contradiction with two recent postulations regarding the subphase stability, one of which suggests that the subphases appear as a result of strong chiral interactions, the other that these phases require high smectic order, something one would generally not expect in mixtures. We have studied the helical pitch, optical tilt angle, spontaneous polarization and the x-ray diffraction due to the smectic layering, as a function of mixing ratio in order to better understand the relation between phase sequence and mixture composition. The smectic layer spacing shows a strongly non-linear behavior, suggesting that the basic structure of the pure AFLC substance is retained up to a HOAB content of about 75%.

antiferroelectric liquid crystals

smectic layer spacing

chirality

smectic order

chiral smectic C subphases

liquid crystal mixtures

Författare

J. P. F. Lagerwall

Universität Stuttgart

Frank Giesselmann

Universität Stuttgart

Sebastien Rauch

Technische Universität Berlin

Gerd Heppke

Technische Universität Berlin

Per Rudquist

Chalmers, Mikroteknologi och nanovetenskap (MC2), Fotonik

Sven Lagerwall

Chalmers, Mikroteknologi och nanovetenskap (MC2), Fotonik

Ferroelectrics

0015-0193 (ISSN)

Vol. 315 221-230

Ämneskategorier

Fysik

DOI

10.1080/00150190490510438

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Senast uppdaterat

2018-03-19