Orientational order in nematic phases determined from polarized optical spectroscopy

1995 ◽  
Author(s):  
Danuta Bauman
Keyword(s):  
Optical Spectroscopy ◽  
Orientational Order ◽  
Nematic Phases ◽  
Polarized Optical Spectroscopy

scholarly journals Study of Orientational Order of Liquid Crystal 8 OCB Doped with Perylene-like Dyes by Means of Polarized Optical Spectroscopy

1996 ◽  
Vol 51 (12) ◽  
pp. 1192-1196 ◽  
Author(s):  
Danuta Bauman ◽  
Eryk Wolarz
Keyword(s):  
Liquid Crystal ◽  
Fluorescence Spectra ◽  
Orientational Order ◽  
Smectic A ◽  
Orientational Distribution ◽  
Nematic Phases ◽  
Polarized Optical Spectroscopy ◽  
Parameter Values ◽  
Orientational Distribution Function ◽  
Orientation Of Molecules

Abstract Measurements of the polarized absorption and fluorescence spectra for perylene-like dyes dis-solved in a liquid crystal 8 OCB have been used to study the long-range orientational order in the smectic A and nematic phases. The temperature dependence of the order parameters <P2> and <P4> has been investigated and the orientational distribution function has been determined. On the basis of the experimental order parameter values some information about the orientation of molecules in guest-host mixtures has been obtained.

The Creutz-Taube complex revisited: polarized optical spectroscopy

1985 ◽  
Vol 24 (6) ◽  
pp. 939-943 ◽  
Author(s):  
Elmars Krausz ◽  
Andreas Ludi
Keyword(s):  
Optical Spectroscopy ◽  
Polarized Optical Spectroscopy

scholarly journals Raman scattering studies of order parameters in liquid crystalline dimers exhibiting the nematic and twist-bend nematic phases

2015 ◽  
Vol 3 (38) ◽  
pp. 10007-10016 ◽  
Author(s):  
Zhaopeng Zhang ◽  
Vitaly P. Panov ◽  
Mamatha Nagaraj ◽  
Richard J. Mandle ◽  
John W. Goodby ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Raman Scattering ◽  
Homologous Series ◽  
Liquid Crystalline ◽  
Orientational Order ◽  
Order Parameters ◽  
Polarized Raman Spectroscopy ◽  
Nematic Phases ◽  
Polarized Raman

The work deduces orientational order parameters in the nematic and twist-bend nematic phases. An homologous series of dimers is studied using Polarized Raman Spectroscopy.

scholarly journals Electro-induced orientational ordering of anisotropic pigment nanoparticles

2013 ◽  
Vol 371 (1988) ◽  
pp. 20120257 ◽  
Author(s):  
Robert J. Greasty ◽  
Robert M. Richardson ◽  
Susanne Klein ◽  
David Cherns ◽  
Michael R. Thomas ◽  
...  
Keyword(s):  
Electric Fields ◽  
Orientational Order ◽  
Optical Response ◽  
Pigment Particle ◽  
X Ray ◽  
X Ray Scattering ◽  
Orientational Ordering ◽  
Nematic Phases ◽  
High Concentrations ◽  
Ray Scattering

The response of anisotropic pigment particle suspensions to externally applied electric fields has been explored for possible application in reflective display technologies. Three different types of pigment particle were suspended in dodecane, using a polymeric stabilizer, and showed Schlieren textures between crossed polarizers at high concentrations (greater than 25–30 wt%), indicating the formation of colloidal nematic phases. Orientational order parameters were determined by X-ray scattering, and the influence of polydispersity on the values is discussed. X-ray scattering measurements also demonstrated a change in the structure factor consistent with the onset of a colloidal nematic phase. In addition, the pigment particles were dispersed into various liquid crystal hosts at low concentrations (less than 5 wt%) with and without the presence of mesogenic mimic stabilizers. However, the influence of these stabilizers on orientational ordering could not be confirmed. The electro-induced ordering determined via scattering was related to the electro-optical response of each suspension using a simple model. The particles in nematic hosts not only showed a high degree of orientational ordering at lower electric field strengths, but also showed a reduction in stability. Although these systems have shown strong orientational ordering, the optical response has been limited by the intrinsic shape of the pigment particles and the distribution of the transition dipoles moments within them. Nevertheless, the feasibility of developing materials for display applications has been demonstrated.

Orientation of chemical bonds at type-II heterointerfaces probed by polarized optical spectroscopy

2000 ◽  
Vol 61 (4) ◽  
pp. R2421-R2424 ◽  
Author(s):  
D. R. Yakovlev ◽  
E. L. Ivchenko ◽  
V. P. Kochereshko ◽  
A. V. Platonov ◽  
S. V. Zaitsev ◽  
...  
Keyword(s):  
Optical Spectroscopy ◽  
Type Ii ◽  
Chemical Bonds ◽  
Polarized Optical Spectroscopy
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