Nematic phase: Difference between revisions

From SklogWiki
Jump to navigation Jump to search
m (→‎Biaxial nematic phase: Added a new review.)
m (Added a new reference.)
Line 1: Line 1:
[[Image:nematic_ellipsoid.png|Nematic phase for the hard 6x1x1 ellipsoid model. |thumb|right]]
[[Image:nematic_ellipsoid.png|Nematic phase for the hard 6x1x1 ellipsoid model. |thumb|right]]
The nematic phase has orientational order, but no positional order.
The '''nematic phase''' of a [[liquid crystals |liquid crystal]] has orientational order, but no positional order
==Discotic nematic phase==
<ref>[http://www.oup.com/us/catalog/general/subject/Physics/MaterialsScience/?view=usa&ci=9780198517856 Pierre-Gilles De Gennes and J. Prost "Physics of Liquid Crystals"  (1995)]</ref>.
[[Image:discotic_nematic_ellipsoid.png|Discotic-nematic phase for the hard 6x6x1 ellipsoid model. |thumb|right]]
==Dielectric tensor==
==Dielectric tensor==
In the uniaxial nematic phase, defining the ''z''-axis to be parallel to the nematic axis, one has
In the uniaxial nematic phase, defining the ''z''-axis to be parallel to the nematic axis, one has
Line 18: Line 17:
The response of a nematic liquid crystal
The response of a nematic liquid crystal
to an external electric field depends on both the sign and the magnitude of <math>\Delta \epsilon</math>.
to an external electric field depends on both the sign and the magnitude of <math>\Delta \epsilon</math>.
==Discotic nematic phase==
[[Image:discotic_nematic_ellipsoid.png|Discotic-nematic phase for the hard 6x6x1 ellipsoid model. |thumb|right]]
==Biaxial nematic phase==
==Biaxial nematic phase==
#[http://dx.doi.org/10.1103/PhysRevLett.97.267801  Jorge Peláez and Mark R. Wilson "Atomistic Simulations of a Thermotropic Biaxial Liquid Crystal", Physical Review Letters '''97''' 267801 (2006)]
*[http://dx.doi.org/10.1103/PhysRevLett.97.267801  Jorge Peláez and Mark R. Wilson "Atomistic Simulations of a Thermotropic Biaxial Liquid Crystal", Physical Review Letters '''97''' 267801 (2006)]
#[http://dx.doi.org/10.1016/j.fluid.2007.03.026  Carl McBride and Enrique Lomba "Hard biaxial ellipsoids revisited: Numerical results", Fluid Phase Equilibria  '''255''' pp. 37-45 (2007)]
*[http://dx.doi.org/10.1016/j.fluid.2007.03.026  Carl McBride and Enrique Lomba "Hard biaxial ellipsoids revisited: Numerical results", Fluid Phase Equilibria  '''255''' pp. 37-45 (2007)]
#[http://dx.doi.org/10.1063/1.2815804 Roberto Berardi, Luca Muccioli, and Claudio Zannoni "Field response and switching times in biaxial nematics", Journal of Chemical Physics '''128''' 024905 (2008)]
*[http://dx.doi.org/10.1063/1.2815804 Roberto Berardi, Luca Muccioli, and Claudio Zannoni "Field response and switching times in biaxial nematics", Journal of Chemical Physics '''128''' 024905 (2008)]
#[http://dx.doi.org/10.1088/0953-8984/20/46/463101  Roberto Berardi, Luca Muccioli, Silvia Orlandi, Matteo Ricci and Claudio Zannoni "Computer simulations of biaxial nematics", Journal of Physics: Condensed Matter '''20''' 463101 (2008)]
*[http://dx.doi.org/10.1088/0953-8984/20/46/463101  Roberto Berardi, Luca Muccioli, Silvia Orlandi, Matteo Ricci and Claudio Zannoni "Computer simulations of biaxial nematics", Journal of Physics: Condensed Matter '''20''' 463101 (2008)]
 
*[http://dx.doi.org/10.1063/1.3117925 Prabir K. Mukherjee and Kallol Sen "On a new topology in the phase diagram of biaxial nematic liquid crystals", Journal of Chemical Physics '''130''' 141101 (2009)]
==References==
==References==
<references/>
[[category: liquid crystals]]
[[category: liquid crystals]]

Revision as of 17:47, 14 April 2009

Nematic phase for the hard 6x1x1 ellipsoid model.

The nematic phase of a liquid crystal has orientational order, but no positional order [1].

Dielectric tensor

In the uniaxial nematic phase, defining the z-axis to be parallel to the nematic axis, one has

The anisotropy is defined as

.

The response of a nematic liquid crystal to an external electric field depends on both the sign and the magnitude of .

Discotic nematic phase

Discotic-nematic phase for the hard 6x6x1 ellipsoid model.

Biaxial nematic phase

References