The influence of structure and concentration of cyano-terminated and terphenyl dopants on helical pitch and helical twist sense in orthoconic antiferroelectric mixtures

Czerwiński, Michał; Tykarska, Marzena; Dąbrowski, R.; Chełstowska, Aleksandra; Żurowska, M.; Kowerdziej, Rafał; Jaroszewicz, Leszek R.

doi:10.1080/02678292.2012.723047

Cited by 28 publications

(10 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The above characteristics (range and invariance of relaxation frequency) suggest that the observed relaxation mode is the Goldstone mode, which is observed due to the phase fluctuation of the directors around the smectic cone. [15,[25][26][27][28][29] Ongoing to the SmB h * phase, two modes have been observed with very low dielectric strength (see Figure 8). The first one (M 3 ) is found in the high kHz region~94 kHz, whereas the other (M 4 ) in MHz region~2 MHz.…”

Section: Dielectric Studiesmentioning

confidence: 94%

Dielectric characterisation of a ferroelectric liquid crystalline material having SmA–SmC–SmB_h* phase sequence

Pandey¹,

Pandey²,

Singh³

et al. 2014

Liquid Crystals

View full text Add to dashboard Cite

Thermodynamical, optical and dielectric characterisation of a material possessing ferroelectric SmC* and hexatic SmB* phases has been carried out. Phase identification has been done by miscibility studies. From the dielectric studies, a relaxation mechanism is observed in the low MHz region of the SmA* phase, which is related to the tilt fluctuation (soft mode) of the directors. In the SmC* phase, another collective relaxation mechanism has been observed in the kHz region, which is related to the phase fluctuation (Goldstone mode) of the directors. In the SmB h * phase, 2-weak relaxation modes are observed in the kHz and MHz frequency range, respectively, due to individual molecular rotations.

show abstract

Section: Dielectric Studiesmentioning

confidence: 94%

Dielectric characterisation of a ferroelectric liquid crystalline material having SmA–SmC–SmB_h* phase sequence

Pandey¹,

Pandey²,

Singh³

et al. 2014

Liquid Crystals

View full text Add to dashboard Cite

show abstract

“…℃FLC material coded as W327, provided to us by Military University of Technology Liquid Crystal group, Warsaw, Poland, is a multicomponent mixture of pyrimidine and pyridine organic compounds with a chiral dopant and their composition is based on results referenced here. [18,19] Mixture W327 has following transition scheme.…”

Section: Methodsmentioning

confidence: 99%

Synchronous Temperature-Voltage Cycle Instigated Memory Effects: Experimental Analysis of SmC* Phase in SiO2 Dispersed Ferroelectric Liquid Crystals

Roy¹,

Srivastava²,

Manohar³

2018

View full text Add to dashboard Cite

The present investigation explores memory behavior in pristine ferroelectric liquid crystals (FLC) and their composites. The induced non-volatile memory traces back its origin from the reconfiguration of helical arrangement of LC molecules under the influence of synchronous cycle of temperature-voltage. The addition of SiO2 quantum dots provides pronounceable memory behavior, which can be applied for coding optical or electrical field motivated LC based storage devices. The measurement of the polarized state of the FLC molecules and their composites has been carried out dielectrically upto 1 h projecting non-volatile memory effects. The analysis of geometrical arrangement of LC molecules and surface effects due to the incorporation of quantum dots and simultaneous stimulations of temperature and voltage cycle has been reckoned in the study. The traps on the surface of the dispersed quantum dots capture mobile ions and force the LC molecules in the vicinity of quantum dots to display reminiscences of switched state. The dispersion of SiO2 ensures efficient memorized orientation in the formulated composites resulting in steady memory behavior.

show abstract

“…It allows to control other parameters important for applications, that is helical parameters. The limited number of antiferroelectric mixtures with long helical pitch [8,[11][12][13][14] as well as continuous development of new fields of application of liquid crystal materials [15][16][17][18] make the formulation of new antiferroelectric mixtures with desired helical parameters a very important action.…”

Section: Introductionmentioning

confidence: 99%

Helix parameters in bi- and multicomponent mixtures composed of orthoconic antiferroelectric liquid crystals with three ring molecular core

Czerwiński

Tykarska²

2014

Liquid Crystals

View full text Add to dashboard Cite

Eight types of bicomponent systems composed of antiferroelectric compounds with different polarity of achiral chain and different temperature dependence of helical pitch as well as three multicomponent mixtures composed of antiferroelectric compounds with opposite helical twist sense were studied. The phase miscibility was tested by polarising optical microscopy. The results of the helical pitch and helical twist sense measurements obtained by a spectrophotometric method of selectively reflected light and by polarimetric method, respectively, are presented. It was found that it is possible to control helical pitch length and temperature of helix twist inversion in antiferroelectric mixtures by controlling the ratio of compounds with left-and right-handed helix in such mixtures, although all of them have the same chiral terminal chain.

show abstract

The influence of structure and concentration of cyano-terminated and terphenyl dopants on helical pitch and helical twist sense in orthoconic antiferroelectric mixtures

Cited by 28 publications

References 18 publications

Dielectric characterisation of a ferroelectric liquid crystalline material having SmA–SmC–SmB_h* phase sequence

Dielectric characterisation of a ferroelectric liquid crystalline material having SmA–SmC–SmB_h* phase sequence

Synchronous Temperature-Voltage Cycle Instigated Memory Effects: Experimental Analysis of SmC* Phase in SiO2 Dispersed Ferroelectric Liquid Crystals

Helix parameters in bi- and multicomponent mixtures composed of orthoconic antiferroelectric liquid crystals with three ring molecular core

Contact Info

Product

Resources

About

The influence of structure and concentration of cyano-terminated and terphenyl dopants on helical pitch and helical twist sense in orthoconic antiferroelectric mixtures

Cited by 28 publications

References 18 publications

Dielectric characterisation of a ferroelectric liquid crystalline material having SmA*–SmC*–SmBh* phase sequence

Dielectric characterisation of a ferroelectric liquid crystalline material having SmA*–SmC*–SmBh* phase sequence

Synchronous Temperature-Voltage Cycle Instigated Memory Effects: Experimental Analysis of SmC* Phase in SiO2 Dispersed Ferroelectric Liquid Crystals

Helix parameters in bi- and multicomponent mixtures composed of orthoconic antiferroelectric liquid crystals with three ring molecular core

Contact Info

Product

Resources

About

Dielectric characterisation of a ferroelectric liquid crystalline material having SmA–SmC–SmB_h* phase sequence

Dielectric characterisation of a ferroelectric liquid crystalline material having SmA–SmC–SmB_h* phase sequence