Phase diagram of octapod-shaped nanocrystals in a quasi-two-dimensional planar geometry

Weikai Qi*, Joost de Graaf, Fen Qiao, Sergio Marras, Liberato Manna, Marjolein Dijkstra

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Recently, we reported the formation of crystalline monolayers consisting of octapod-shaped nanocrystals (so-called octapods) that had arranged in a square-lattice geometry through drop deposition and fast evaporation on a substrate [W. Qi, J. de Graaf, F. Qiao, S. Marras, L. Manna, and M. Dijkstra, Nano Lett. 12, 5299 (2012)]. In this paper we give a more in-depth exposition on the Monte Carlo simulations in a quasi-two-dimensional (quasi-2D) geometry, by which we modelled the experimentally observed crystal structure formation. Using a simulation model for the octapods consisting of four hard interpenetrating spherocylinders, we considered the effect of the pod length-to-diameter ratio on the phase behavior and we constructed the full phase diagram. The methods we applied to establish the nature of the phase transitions between the various phases are discussed in detail. We also considered the possible existence of a Kosterlitz-Thouless-type phase transition between the isotropic liquid and hexagonal rotator phase for certain pod length-to-diameter ratios. Our methods may prove instrumental in guiding future simulation studies of similar anisotropic nanoparticles in confined geometries and monolayers. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4799269]

Original languageEnglish
Article number154504
Number of pages13
JournalThe Journal of Chemical Physics
Volume138
Issue number15
DOIs
Publication statusPublished - 21 Apr 2013

Keywords

  • COLLOIDAL NANOCRYSTALS
  • 2 DIMENSIONS
  • BEHAVIOR
  • SOLIDS
  • SUPERLATTICES
  • CRYSTALLINE
  • TRANSITIONS
  • PARTICLES
  • SQUARES
  • BINARY

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