Nematic phase: Difference between revisions
		
		
		
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[[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  | ||
<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>.  | |||
[  | |||
==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>.  | ||
==Chiral nematic phase==  | |||
See [[Chiral phases]].  | |||
==Discotic nematic phase==  | |||
[[Image:discotic_nematic_ellipsoid.png|Discotic-nematic phase for the hard 6x6x1 ellipsoid model. |thumb|right]]  | |||
==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/10.1016/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/10.1088/0953-8984/20/46/463101   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)]  | |||
*[http://przyrbwn.icm.edu.pl/APP/ABSTR/120/a120-3-1.html A. Kapanowski "Statistical Theory of Biaxial Nematic and Cholesteric Phases", Acta Physica Polonica A '''120''' pp. 351-367 (2011)]  | |||
*[http://dx.doi.org/10.1063/1.3646310 Roberto Berardi, Juho S. Lintuvuori, Mark R. Wilson, and Claudio Zannoni "Phase diagram of the uniaxial and biaxial soft–core Gay–Berne model", Journal of Chemical Physics '''135''' 134119 (2011)]  | |||
*[http://dx.doi.org/10.1063/1.4771592  Akihiko Matsuyama "Novel biaxial nematic phases of side-chain liquid crystalline polymers", Journal of Chemical Physics '''137''' 224906 (2012)]  | |||
* Geoffrey R. Luckhurst, Timothy J. Sluckin (Eds.) "Biaxial Nematic Liquid Crystals: Theory, Simulation and Experiment", Wiley-Blackwell (2011) ISBN 1444304550  | |||
==References==  | ==References==  | ||
<references/>  | |||
[[category: liquid crystals]]  | [[category: liquid crystals]]  | ||
Latest revision as of 13:15, 30 March 2016

The nematic phase of a liquid crystal has orientational order, but no positional order [1].
Dielectric tensor[edit]
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 .
Chiral nematic phase[edit]
See Chiral phases.
Discotic nematic phase[edit]

Biaxial nematic phase[edit]
- Jorge Peláez and Mark R. Wilson "Atomistic Simulations of a Thermotropic Biaxial Liquid Crystal", Physical Review Letters 97 267801 (2006)
 - Carl McBride and Enrique Lomba "Hard biaxial ellipsoids revisited: Numerical results", Fluid Phase Equilibria 255 pp. 37-45 (2007)
 - Roberto Berardi, Luca Muccioli, and Claudio Zannoni "Field response and switching times in biaxial nematics", Journal of Chemical Physics 128 024905 (2008)
 - Roberto Berardi, Luca Muccioli, Silvia Orlandi, Matteo Ricci and Claudio Zannoni "Computer simulations of biaxial nematics", Journal of Physics: Condensed Matter 20 463101 (2008)
 - 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)
 - A. Kapanowski "Statistical Theory of Biaxial Nematic and Cholesteric Phases", Acta Physica Polonica A 120 pp. 351-367 (2011)
 - Roberto Berardi, Juho S. Lintuvuori, Mark R. Wilson, and Claudio Zannoni "Phase diagram of the uniaxial and biaxial soft–core Gay–Berne model", Journal of Chemical Physics 135 134119 (2011)
 - Akihiko Matsuyama "Novel biaxial nematic phases of side-chain liquid crystalline polymers", Journal of Chemical Physics 137 224906 (2012)
 - Geoffrey R. Luckhurst, Timothy J. Sluckin (Eds.) "Biaxial Nematic Liquid Crystals: Theory, Simulation and Experiment", Wiley-Blackwell (2011) ISBN 1444304550