title: Development of Polar Order in the Liquid Crystal Phases of a 4-Cyanoresorcinol-Based Bent-Core Mesogen with Fluorinated Azobenzene Wings.
abstract: A bent-core mesogen consisting of a 4-cyanoresorcinol unit as the central core and laterally fluorinated azobenzene wings forms four different smectic LC phase structures in the sequence SmA-SmCs -SmCs PAR -M, all involving polar SmCs PS domains with growing coherence length of tilt and polar order on decreasing temperature. The SmA phase is a cluster-type de Vries phase with randomized tilt and polar direction; in the paraelectric SmCs phase the tilt becomes uniform, although polar order is still short-range. Increasing polar correlation leads to a new tilted and randomized polar smectic phase with antipolar correlation between the domains (SmCs PAR ) which then transforms into a viscous polar mesophase M. As another interesting feature, spontaneous symmetry breaking by formation of a conglomerate of chiral domains is observed in the non-polar paraelectric SmCs phase.
authors.affiliation: Institute of Chemistry, Organic Chemistry, Martin Luther University Halle-Wittenberg, Kurt-Mothes Str. 2, 06120, Halle/Saale, Germany. malaasar@sci.cu.edu.eg.|Department of Chemistry, Faculty of Science, Cairo University, Giza, Egypt. malaasar@sci.cu.edu.eg.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Alaasar
authors.affiliation: Institute of Chemistry, Organic Chemistry, Martin Luther University Halle-Wittenberg, Kurt-Mothes Str. 2, 06120, Halle/Saale, Germany.
authors.forename: Marko
authors.initials: M
authors.lastname: Prehm
authors.affiliation: Institute for Experimental Physics, Otto-von-Guericke University Magdeburg, Universitätsplatz 2, 39106, Magdeburg, Germany.
authors.forename: Maria-Gabriela
authors.initials: MG
authors.lastname: Tamba
authors.affiliation: Institute for Experimental Physics, Otto-von-Guericke University Magdeburg, Universitätsplatz 2, 39106, Magdeburg, Germany.
authors.forename: Nerea
authors.initials: N
authors.lastname: Sebastián
authors.affiliation: Institute for Experimental Physics, Otto-von-Guericke University Magdeburg, Universitätsplatz 2, 39106, Magdeburg, Germany. alexey.eremin@ovgu.de.
authors.forename: Alexey
authors.initials: A
authors.lastname: Eremin
authors.affiliation: Institute of Chemistry, Organic Chemistry, Martin Luther University Halle-Wittenberg, Kurt-Mothes Str. 2, 06120, Halle/Saale, Germany. carsten.tschierske@chemie.uni-halle.de.
authors.forename: Carsten
authors.identifier: http://orcid.org/0000-0002-4163-3272
authors.initials: C
authors.lastname: Tschierske
keywords: azobenzene; bent-core liquid crystals; de Vries phase; ferroelectricity; mirror symmetry breaking