Journal ArticleDOI
Evidence of Tricritical Behavior at the Nematic Isotropic Transition
TLDR
In this article, the authors derived the value of the ratio (Q*-QNI)/QNI, where Q* is the order parameter at the temperature T* of the absolute stability limit of the isotropic phase and QNI is the condition at the nematic-isotropic transition temperature TNI.Abstract:
Tricritical behavior at the nematic–isotropic phase transition is discussed by means of Landau–de Gennes phenomenological theory. The temperature difference TNI-T* is obtained near the tricritical point. We also obtained the value of the ratio (Q*-QNI)/QNI, where Q* is the order parameter at the temperature T* of the absolute stability limit of the isotropic phase and QNI is the order parameter at the nematic–isotropic transition temperature TNI. As a definite improvement over the earlier attempts utilizing Landau–de Gennes scheme the present work can reproduce low values of (Q*-QNI)/QNI and that of TNI-T* as demanded by experimental observations. The tricritical exponents are calculated from the scaling theory and compared with observed values. Using the Ginzburg criterion, we also determine the critical region of the nematic–isotropic phase transition.read more
Citations
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Journal ArticleDOI
Cotton-Mouton constants and pretransitional phenomena in the isotropic phase of liquid crystals
TL;DR: The Cotton-Mouton constants for three homologous series of liquid crystals were measured in the isotropic phase as mentioned in this paper, and the results were compared with theories on pretransitional phenomena.
Book ChapterDOI
On the Tricritical Point of the Isotropic — Nematic Transition in a Rod-Like Mesogen Hidden in the Negative Pressure Region
TL;DR: In this article, a presentation of experimental results suggesting fluidlike, spinodal and tricritical nature of the isotropic-nematic transition are given. Results presented based on broad-band dielectric spectroscopy and strong electric field induced changes of dielectrics permittivity.
Book ChapterDOI
The Discontinuity of the Isotropic — Masophase Transition in N-Cyanobiphenyls Homologous Series from 4CB to 14CB. Nonlinear Dielectric Effect (NDE) Studies
TL;DR: In this article, the static nonlinear dielectric effect (NDE) in homologous series of 4-cyano-4-n-alkylbiphenyls (nCB, from n=3 to n=14), exhibiting both isotropic - nematic (I-N) and isotropicsmectic A (I -SmA) phase transitions, are presented.
Journal ArticleDOI
Phase equilibria in solutions of platelike particles: systems with steric and dispersive interactions between the platelets.
TL;DR: Numerical calculations show that besides the isotropic- nematic biphasic coexistence range, inclusion of attractive forces resulted in the appearance of nematic-nematic coexistence in both, disks and rods, solutions.
References
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Journal ArticleDOI
Static Phenomena Near Critical Points: Theory and Experiment
Leo P. Kadanoff,Wolfgang Götze,David Hamblen,Robert Hecht,E. A. S. Lewis,V. V. Palciauskas,Martin Rayl,Jack Swift,D. E. Aspnes,Joseph W. Kane +9 more
TL;DR: In this paper, the authors compared theory and experiment for behavior very near critical points, and suggested that scaling laws provide a promising approach to understand phenomena near the critical point, but that they are by no means proved or disproved by the existing experimental data.
Journal ArticleDOI
Eine einfache molekulare Theorie des nematischen kristallinflüssigen Zustandes
W. Maier,Alfred Saupe +1 more
Journal ArticleDOI
Phenomenology of short-range-order effects in the isotropic phase of nematic materials
TL;DR: In this article, the magnetic birefringence, the intensity and the width in frequency of the Rayleigh scattering, and the flow bireringence are discussed in terms of a small number of phenomenological parameters.
Journal ArticleDOI
Landau theory of the nematic-isotropic phase transition
TL;DR: A review of the wide variety of predictions that results from a Landau-type of description of the nematic-isotropic phase transition is given in this paper, which includes a discussion of the nature of the order parameter and of the various types of possible phases.
Journal ArticleDOI
Monte Carlo Study of the Isotropic-Nematic Transition in a Fluid of Thin Hard Disks
Daan Frenkel,Rob Eppenga +1 more
TL;DR: The first numerical determination of the thermodynamic isotropic-nematic transition in a simple three-dimensional model fluid, viz., a system of infinitely thin hard platelets, is reported in this article.