### Mesocrystal

This examples deals with the modelling of a cylindrically shaped mesocrystal on a substrate. With this scope, three lattice basis vectors are defined, using spherical particles as the base of a first crystal structure. This base crystal structure is later combined with a cylinder form factor to form the mesocrystal.

The basis vectors of the base crystal are $5 \, {\rm nm}$ each, the sperical particles have a radius of $2 \, {\rm nm}$ and the cylindrical form factor to shape the mesocrystal is $20 \, {\rm nm}$ in radius and $50 \, {\rm nm}$ in height.

  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 66 67 68 69 70 71  """ Cylindrical mesocrystal on a substrate """ import bornagain as ba from bornagain import deg, angstrom, nm def get_sample(): """ Returns a sample with a cylindrically shaped mesocrystal on a substrate. """ # defining materials m_ambience = ba.HomogeneousMaterial("Air", 0.0, 0.0) m_substrate = ba.HomogeneousMaterial("Substrate", 6e-6, 2e-8) m_particle = ba.HomogeneousMaterial("Particle", 6e-4, 2e-8) # mesocrystal lattice lattice_basis_1 = ba.kvector_t(5.0, 0.0, 0.0) lattice_basis_2 = ba.kvector_t(0.0, 5.0, 0.0) lattice_basis_3 = ba.kvector_t(0.0, 0.0, 5.0) lattice = ba.Lattice(lattice_basis_1, lattice_basis_2, lattice_basis_3) # spherical particle that forms the base of the mesocrystal sphere_ff = ba.FormFactorFullSphere(2*nm) sphere = ba.Particle(m_particle, sphere_ff) # crystal structure crystal = ba.Crystal(sphere, lattice) # mesocrystal meso_ff = ba.FormFactorCylinder(20 * nm, 50 * nm) meso = ba.MesoCrystal(crystal, meso_ff) particle_layout = ba.ParticleLayout() particle_layout.addParticle(meso) air_layer = ba.Layer(m_ambience) air_layer.addLayout(particle_layout) substrate_layer = ba.Layer(m_substrate) multi_layer = ba.MultiLayer() multi_layer.addLayer(air_layer) multi_layer.addLayer(substrate_layer) return multi_layer def get_simulation(): """ Returns a GISAXS simulation with beam and detector defined """ simulation = ba.GISASSimulation() simulation.setDetectorParameters(200, -2.0*deg, 2.0*deg, 200, 0.0*deg, 2.0*deg) simulation.setBeamParameters(1.0*angstrom, 0.2*deg, 0.0*deg) return simulation def run_simulation(): """ Runs simulation and returns intensity map. """ simulation = get_simulation() simulation.setSample(get_sample()) simulation.runSimulation() return simulation.result() if __name__ == '__main__': result = run_simulation() ba.plot_simulation_result(result, cmap='jet', aspect='auto') 
MesoCrystal.py