Spontaneous and field-induced mesomorphism of a silyl-terminated bent-core liquid crystal as determined from second-harmonic generation and resonant X-ray scattering

被引：19

作者：

Folcia, C. L. ^{[1
]}

Ortega, J. ^{[2
]}

Etxebarria, J. ^{[1
]}

Rodriguez-Conde, S. ^{[1
]}

Sanz-Enguita, G. ^{[2
]}

Geese, K. ^{[3
]}

Tschierske, C. ^{[3
]}

Ponsinet, V. ^{[4
]}

Barois, P. ^{[4
]}

Pindak, R. ^{[5
]}

Pan, LiDong ^{[6
,9
]}

Liu, Z. Q. ^{[7
]}

McCoy, B. K. ^{[8
]}

Huang, C. C. ^{[9
]}

机构：

[1] Univ Basque Country, UPV EHU, Dept Condensed Matter Phys, Bilbao 48080, Spain

[2] Univ Basque Country, UPV EHU, Dept Appl Phys 2, Bilbao 48080, Spain

[3] Univ Halle Wittenberg, Inst Chem, D-06120 Halle, Germany

[4] Univ Bordeaux, CNRS, CRPP, UPR8641, F-33600 Pessac, France

[5] Brookhaven Natl Lab, Photon Sci Directorate, Upton, NY 11973 USA

[6] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA

[7] St Cloud State Univ, Dept Chem & Phys, St Cloud, MN 56301 USA

[8] Azusa Pacific Univ, Dept Math & Phys, Azusa, CA 91702 USA

[9] Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA

来源：

SOFT MATTER | 2014年 / 10卷 / 01期

关键词：

POLAR ORDER; SUPERSTRUCTURAL CHIRALITY; SHAPED COMPOUNDS; SMECTIC PHASE; MOLECULES; SUSCEPTIBILITY; DENDRIMER; DESIGN; BLOCK; UNITS;

D O I：

10.1039/c3sm51277k

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The polarity and structure of the phases of a liquid crystal constituted by thiophene-based bent-core molecules is investigated by means of optical second-harmonic generation (SHG), and resonant and conventional X-ray diffraction. The material studied is representative of a wide family of mesogens that contain silyl groups at the ends of the chains. These bulky terminal groups have been reported to give rise to smectic phases showing ferroelectric switching. However, the analysis of the SHG signal before and after application of electric fields has allowed us to establish unambiguously that the reported ferroelectricity is not intrinsic to the material but stabilized by the cell substrates once an electric field has been applied. In addition, the results obtained from resonant X-ray diffraction indicate that virgin samples have antiferroelectric undulated synclinic smectic structures.

引用

页码：196 / 205

页数：10

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