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Disordered 3D particle assemblies

Class Dilute3D models random assemblies of particles dispersed in the bulk of a layer. It can be used for thin films as long as the film thickness is greater than the particle diameter.

Possible applications are

  • nanoparticle-filled polymer films,
  • colloidal suspensions, and
  • any other system where particles (or holes) are dispersed in a matrix.

Creating a 3D assembly

To fill a layer with randomly distributed particles:

layer = ba.Layer(matrix_material, thickness)
layer.fill3D(ba.Dilute3D(density, particle))

If the layer contains an incoherent mixture of the disordered assembly and something else, use add3D with a coverage parameter:

layer = ba.Layer(matrix_material, thickness)
disordered = ba.Dilute3D(density, particle)
layer.add3D(coverage, disordered)

Parameters:

  • density: Volume number density in nm⁻³ (particles per cubic nanometer)
  • particle: The particle to distribute throughout the layer
  • coverage (second form only): surface coverage, between 0 and 1

Requirements

3D assemblies require material averaging to be enabled (the default). The layer thickness must be finite and larger than the particle size.

Examples

Dilute film

Spherical nanoparticles dispersed in a substrate layer:

Scattering from dilute film

Open the Dilute film example.

Film vs monolayer

Comparison between a 3D film (fill3D) and a 2D monolayer (deposit2D). As film thickness increases, the scattering pattern evolves from the monolayer limit:

Film thickness dependence

Open the Film vs monolayer example.