### Triangular Ripples in a Rectangular Lattice

Scattering from elongated particles positioned in a two-dimensional rectangular lattice.

• Each particle has a triangular profile (“Ripple2” form factor) with a length of $100$ nm, a width of $20$ nm and a height of $4$ nm.
• They are placed along a rectangular lattice on top of a substrate.
• This lattice is characterized by a lattice length of $200$ nm in the direction of the long axis of the particles and of $50$ nm in the perpendicular direction.
• The lattice’s base vectors coincide with the reference Cartesian frame.
• The wavelength is equal to $1.6$ $\unicode{x212B}$.
• The incident angles are $\alpha_i = 0.3 ^{\circ}$ and $\varphi_i = 0^{\circ}$.

View the example on Cosine Ripples on a Rectangular Lattice for comparison.

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65  #!/usr/bin/env python3 """ Sample from the article D. Babonneau et. al., Phys. Rev. B 85, 235415, 2012 (Fig.3) """ import bornagain as ba from bornagain import deg, nm def get_sample(): """ Returns a sample with a grating on a substrate, modelled by triangular ripples forming a 1D Paracrystal. """ # 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) # Define form factors ff = ba.FormFactorSawtoothRippleBox(100*nm, 20*nm, 4*nm, -3*nm) # Define particles particle = ba.Particle(material_Particle, ff) # Define 2D lattices lattice = ba.BasicLattice2D(200*nm, 50*nm, 90*deg, 0) # Define interference functions iff = ba.InterferenceFunction2DLattice(lattice) iff_pdf = ba.FTDecayFunction2DGauss(160*nm, 16*nm, 0) iff.setDecayFunction(iff_pdf) # Define particle layouts layout = ba.ParticleLayout() layout.addParticle(particle) layout.setInterferenceFunction(iff) layout.setTotalParticleSurfaceDensity(0.0001) # 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, 0.16*nm, ba.Direction(0.3*deg, 0)) detector = ba.SphericalDetector(200, -1.5*deg, 1.5*deg, 200, 0, 2.5*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) 
TriangularRipple.py