Dielectric Spectroscopy of Bent-Core Thioesters' B Phases

Unusual physical properties inBphase of polar bent-core thioester compound

“…A general symbol of B 2 phase is as follows: SmC SA P FA , where index ''S'' stands for synclinic, A for anti-clinic order of molecules in the layers, and F for ferroelectric, A for anti-ferroelectric order of polarization vectors. Recent studies [3,7,10,14,15] performed on a few homologous series show that compounds with shorter side chains (C 5 -C 9 ) exhibit only a frustrated B 1 phase, whereas those having longer chains (C 10 -C 14 ) generally display anti-ferroelectric B 2 phase. The main objective of this article is to present dielectric and electro-optic behavior of 4-chloro-1,3-phenylene bis{4-[(n-undecyloxybenzoyl)-sulfanyl]benzoate} (11OSORCl), which exhibits enantiotropic ferroelectric B F phase.…”

“…As known, banana-shaped compounds may form lamellar smectic mesophases that in the last decades have become a subject of intensive experimental [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] and theoretical [16,17] studies. The most fascinating feature of such systems is that they are non-chiral on molecular level but they show chirality on macroscopic level, which leads to interesting ferroelectric and/or anti-ferroelectric properties.…”

Ferroelectric Liquid Crystals Composed of Banana-Shaped Thioesters

“…Using the latter it was possible to record the reversal current spectra for the B 2 phase in form of two well separated current peaks what substantiates antiferroelectric order of this phase. As also found, the B 1 exhibits also some kind of ferroelectric order which is being gradually reduced upon temperature decreasing (Wierzejska-Adamowicz, 2010;Chruściel, 2011).…”

“…In calamitic LCs the adequate contribution to the dielectric absorption is usually described by the well know term: σ/(ε o ω). As found for bow-shaped systems (Schmalfuss et al, 1999;Kresse et al, 2001, Chruściel et al, 2011 this term should be modified by introducing the M parameter (Eq. (3a)) to obtain better agreement between theory and experiment.…”

“…It has been shown by means of the dielectric spectroscopy (Ossowska- Chruściel et al, 2009;WierzejskaAdamowicz et al, 2010;Chruściel, 2011) that with electric measuring fields being parallel to the polar director p one observes an enhanced dielectric absorption and electric permittivity as well. As found in scope of this work there is an asymmetry of the dielectric spectra between the positive and negative bias fields ( Fig.…”