Core-and-shell nanoparticles

Scattering from cuboidal core-shell particles.

  • The sample is made of core-shell particles whose outer and inner shells are boxes with dimensions $L_1 = W_1 = 16$ nm, $H_1 = 8$ nm and $L_2 = W_2 = 12$ nm, $H_2 = 7$ nm, respectively, where $L_i$, $W_i$ and $H_i$ are the length, width and height of box $i$.
  • The smaller box is positioned so that the centres of the bottom faces of both particles coincide.
  • The simulation is run using the Born approximation. There is no substrate and no interference between the different scattered beams.
  • The planar distribution of the particles is diluted and random.
  • The incident wavelength is equal to 0.1 nm.
  • 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
"""
Core shell nanoparticles
"""
import bornagain as ba
from bornagain import ba_plot as bp, deg, nm, std_samples


def get_sample():
    """
    Returns a sample with box-shaped core-shell particles.
    """

    # Define materials
    material_Core = ba.RefractiveMaterial("Core", 6e-5, 2e-8)
    material_Shell = ba.RefractiveMaterial("Shell", 1e-4, 2e-8)

    # Define form factors
    ff_1 = ba.Box(12*nm, 12*nm, 7*nm)
    ff_2 = ba.Box(16*nm, 16*nm, 8*nm)

    # Define particles
    core = ba.Particle(material_Core, ff_1)
    shell = ba.Particle(material_Shell, ff_2)
    particle = ba.CoreAndShell(shell, core)

    return std_samples.sas_sample_with_particle(particle)


def get_simulation(sample):
    beam = ba.Beam(1, 0.1*nm, ba.Direction(0.2*deg, 0))
    detector = ba.SphericalDetector(bp.simargs['n'], 2*deg, 0, 1*deg)
    simulation = ba.ScatteringSimulation(beam, sample, detector)
    return simulation


if __name__ == '__main__':
    bp.parse_args(sim_n=200)
    sample = get_sample()
    simulation = get_simulation(sample)
    result = simulation.simulate()
    bp.plot_simulation_result(result)
Examples/scatter2d/CoreShellNanoparticles.py

Validated through an alternative implementation that uses particle composition, Examples/scatter2d/CoreShellNanoparticles2.py .