Dynamics of the nonlinear dielectric properties of a nematogenic compound dissolved in a nonpolar medium

Kędziora, P.; Jadżyn, Jan; Hellemans, Louis

doi:10.1103/physreve.66.021709

Cited by 27 publications

(26 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the work of Kedziora et al [12] the coexistence of nematic and isotropic phases in 6CHBT liquid crystal dissolved in a nonpolar medium (benzene) was observed in the vicinity of the temperature of the isotropic-nematic transition. Due to the existence of a short-range orientational order of the mesogenic molecules (6CHBT), pseudonematic domains (droplets of 500-1000 nm in size depending on the temperature) were formed in the isotropic phase.…”

Section: Introductionmentioning

confidence: 97%

The structural transitions in 6CHBT-based ferronematic droplets

Tomašovičová

Kopčanský

Koneracká

et al. 2008

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

In this work we describe the observations of structural transitions in ferronematics based on the thermotropic nematics 6CHBT (4-trans-4'-n-hexyl-cyclohexyl-isothiocyanato-benzene). The ferronematic droplets were observed in solutions of nematogenic 6CHBT dissolved in phenyl isocyanate and doped with fine magnetic particles. The phase diagram of the transitions from the isotropic phase to the nematic phase via a droplet state was found. Magneto-dielectric measurements of various structural transitions in this new system enabled us to estimate the type of anchoring of the nematic molecules on the magnetic particle surfaces in the droplets.

show abstract

Section: Introductionmentioning

confidence: 97%

The structural transitions in 6CHBT-based ferronematic droplets

Tomašovičová

Kopčanský

Koneracká

et al. 2008

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…Another study [20] was inspired by the work of Kedziora et al [21], where a coexistence of nematic and isotropic phases was observed in 6CHBT dissolved in a nonpolar medium (benzene) in the vicinity of the isotropic-to-nematic phase transition temperature.…”

Section: The Structural Transitions In 6chbt-based Ferronematic Dropletsmentioning

confidence: 99%

How to Enhance Sensitivity of Liquid Crystals to External Magnetic Field?

et al. 2015

View full text Add to dashboard Cite

Liquid crystals, due to their large dielectric anisotropy, respond very sensitively to application of an external electric eld, whereas they are only weakly sensitive to the magnetic eld. A possible way of improving that sensitivity is doping liquid crystals with magnetic nanoparticles. As a result, stable colloidal suspensions of liquid crystals with relatively low concentrations of magnetic nanoparticles (called ferronematics, ferrocholesterics, ferrosmectics, etc.) can be produced. We illustrate some examples of the inuence of the magnetic eld, as well as of a superposition of magnetic and electric elds on the structural transitions (e.g. on the Fréedericksz transition) in ferronematics based on the calamitic liquid crystal 4-(trans-4'-n-hexylcyclohexyl)-isothiocyanatobenzene (6CHBT). It is shown that the samples respond to the applied magnetic eld of low strength. The eects of the magnetic particles and magnetic eld on the nematic to isotropic phase transition temperature are discussed as well.

show abstract

“…As far as the order parameter or r-EEM is concerned, both can be reduced effectively either by increasing the temperature or by increasing the concentration of some nonmesogenic isotropic liquid solvent. 10–12 The latter is the indispensable element of our novel approach. In this paper, our novel approach shows the existence of BPs over a wide range of temperature Δ T = 28 °C (290–318 K) including the room temperature.…”

Section: Introductionmentioning

confidence: 99%

Isotropic Elastic Stress Induced Large Temperature Range Liquid Crystal Blue Phase at Room Temperature

Manna

Dupont

2016

J. Phys. Chem. C

View full text Add to dashboard Cite

A thermodynamically stable blue phase (BP) based on the conventional rod like nematogen is demonstrated for the first time at room temperature by only diluting a chiral–nematic mixture with the help of some nonmesogenic isotropic liquid. It is observed that addition of this isotropic liquid does not only stabilize the BPs at room temperature, but also significantly improves the temperature range (reversible during heating and cooling) of the BPs to the level of more than 28 °C. Apart from that, we have observed its microsecond electro-optic response time and, external electric field induced wavelength tuning, which are the two indispensable requirements for next generation optical devices, photonic displays, lasers, and many more. Here we propose that the isotropic liquid plays two crucial roles simultaneously. On one hand, it reduces the effective elastic moduli (EEM) of the BP mixtures and stabilizes the BPs at room temperature, and on the other hand, it increases the symmetry of the mutual orientation ordering among the neighboring unit cells of the BP. Hence, the resultant mixture becomes better resistive to some microscopic change due to the change in temperature, even over a large range.

show abstract

Dynamics of the nonlinear dielectric properties of a nematogenic compound dissolved in a nonpolar medium

Cited by 27 publications

References 24 publications

The structural transitions in 6CHBT-based ferronematic droplets

The structural transitions in 6CHBT-based ferronematic droplets

How to Enhance Sensitivity of Liquid Crystals to External Magnetic Field?

Isotropic Elastic Stress Induced Large Temperature Range Liquid Crystal Blue Phase at Room Temperature

Contact Info

Product

Resources

About