Rotated Pyramids

Scattering from a monodisperse distribution of rotated pyramids.

This example illustrates how the in-plane rotation of non-radially symmetric particles influences the scattering pattern.

  • The sample is made of pyramids deposited on a substrate.
  • Each pyramid is characterized by a squared-base side length of $10$ nm, a height of $5$ nm, and a base angle $\alpha$ equal to $54.73^{\circ}$.
  • These particles are rotated in the $(x, y)$ plane by $45^{\circ}$.
  • There is no interference between the scattered waves.
  • The wavelength is equal to $1$ $\unicode{x212B}$.
  • The incident angles are $\alpha_i = 0.2 ^{\circ}$ and $\varphi_i = 0^{\circ}$.

Real-space model

Intensity image

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#!/usr/bin/env python3
"""
Rotated pyramids on top of substrate
"""
import bornagain as ba
from bornagain import deg, nm


def get_sample():
    """
    Returns a sample with rotated pyramids on top of a substrate.
    """

    # Define materials
    material_Particle = ba.HomogeneousMaterial("Particle", 0.0006, 2e-08)
    material_Substrate = ba.HomogeneousMaterial("Substrate", 6e-06, 2e-08)
    material_Vacuum = ba.HomogeneousMaterial("Vacuum", 0.0, 0.0)

    # Define form factors
    ff = ba.FormFactorPyramid(10.0*nm, 5.0*nm, 54.73*deg)

    # Define particles
    particle = ba.Particle(material_Particle, ff)
    particle_rotation = ba.RotationZ(45.0*deg)
    particle.setRotation(particle_rotation)

    # Define particle layouts
    layout = ba.ParticleLayout()
    layout.addParticle(particle, 1.0)
    layout.setWeight(1)
    layout.setTotalParticleSurfaceDensity(0.01)

    # Define layers
    layer_1 = ba.Layer(material_Vacuum)
    layer_1.addLayout(layout)
    layer_2 = ba.Layer(material_Substrate)

    # Define sample
    sample = ba.MultiLayer()
    sample.addLayer(layer_1)
    sample.addLayer(layer_2)

    return sample


def get_simulation(sample):
    beam = ba.Beam(1.0, 0.1*nm, ba.Direction(0.2*deg, 0*deg))
    detector = ba.SphericalDetector(200, -2*deg, 2*deg, 200, 0*deg, 2*deg)
    simulation = ba.GISASSimulation(beam, sample, detector)
    return simulation


if __name__ == '__main__':
    import ba_plot
    sample = get_sample()
    simulation = get_simulation(sample)
    ba_plot.run_and_plot(simulation)
RotatedPyramids.py