Biaxial nematic and smectic phases of parallel particles with different cross sections

Yuri Martínez-Ratón, S. Varga, Enrique Velasco

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

We have calculated the phase diagrams of one-component fluids made of five types of biaxial particles differing in their cross sections. The orientation of the principal particle axis is fixed in space, while the second axis is allowed to freely rotate. We have constructed a free-energy density functional based on fundamental-measure theory to study the relative stability of nematic and smectic phases with uniaxial, biaxial, and tetratic symmetries. Minimization of the density functional allows us to study the phase behavior of the biaxial particles as a function of the cross-section geometry. For low values of the aspect ratio of the particle cross section, we obtain smectic phases with tetratic symmetry, although metastable with respect to the crystal, as our Monte Carlo simulation study indicates. For large particle aspect ratios and in analogy with previous work, we have found a four-phase point where four spinodals, corresponding to phase transitions between phases with different symmetries, meet together. The location of this point is quite sensitive to particle cross section, which suggests that optimizing the particle geometry could be a useful criterion in the design of colloidal particles that can exhibit an increased stability of the biaxial nematic phase with respect to other competing phases with spatial order.

Original languageEnglish
Article number031705
JournalPhysical Review E - Statistical, Nonlinear, and Soft Matter Physics
Volume78
Issue number3
DOIs
Publication statusPublished - Sep 9 2008

Fingerprint

Biaxial
Cross section
cross sections
Symmetry
Density Functional
Aspect Ratio
aspect ratio
symmetry
Relative Stability
Measure Theory
geometry
Energy Density
Phase Diagram
Analogy
Free Energy
Crystal
Phase Transition
flux density
Monte Carlo Simulation
free energy

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Condensed Matter Physics
  • Statistical and Nonlinear Physics
  • Mathematical Physics

Cite this

Biaxial nematic and smectic phases of parallel particles with different cross sections. / Martínez-Ratón, Yuri; Varga, S.; Velasco, Enrique.

In: Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, Vol. 78, No. 3, 031705, 09.09.2008.

Research output: Contribution to journalArticle

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