bornagain software: simulating and fitting grazing...

Concepts of BornAgain

Motivations

BornAgain software: simulating and fitting grazing-incidence small-angle scattering from assemblies of nanoparticles

C. Durniak, M. Ganeva, P. Pospelov, W. Van Herck, J. Wuttke

Jülich Centre for Neutron Science (JCNS) at MLZ, Forschungszentrum Jülich GmbH, Garching, Germany

BornAgain:

-  open source software package to simulate and fit small angle scattering at grazing incidence.

-  provides a generic framework for modeling multilayer samples with smooth or rough interfaces and with various types of embedded nanoparticles.

Conclusion

[1] G. Renaud, R. Lazzari, F. Leroy, Probing surface and interface morphology with Grazing Incidence Small Angle X-Ray Scattering, Surface Science Reports 64, 255 (2009).

[2] http://bornagainproject.org

References

Scattering intensity = function of particles (shapes, sizes), distributions of particles, layers of materials.

Examples

Contact: c.durniak@fz-juelich.de Phone: +49.89.289.11678

✓  Support for multilayers ✓  Interface roughness correlation ✓ Magnetic materials

✓ Multiple type of nanoparticles (~20 shapes)

Particles

✓  Lattices ✓  Disordered systems ✓ Short-range order distribution ✓ Size-spacing distribution ✓ Deposited / embedded particles

Positions of particles

✓ Divergence of the input beam (wavelength, angles…) following different distributions ✓ Polarized neutrons ✓ Off specular scattering ✓ 2D detector

Beam / detector

✓ Simulation / Fitting ✓ Python scripting or Graphical User Interface

Use of BornAgain

✓ Particles with inner structures ✓ Assemblies of particles

✓ Size distribution

Geometry of a GISAS experiment

Ag cuboctahedral particles distributed along an hexagonal lattice, deposited on Al2O3, Si layers.

Random distribution of Au truncated spheres and spheroids with Cu spherical cores deposited on SiO2 and Si layers.

Hexagonal lattice Core-shell

Grazing incidence small angle scattering (GISAS):

-  surface sensitive, non destructive technique -  large area coverage g statistical information

-  tunable depth probe by changing input angle -  use of X-ray or neutrons to scan different

properties -  characterisation of deposited or embedded

nanoparticles, layered materials [1]

Challenging data analysis in reciprocal space:

-  multiple reflections at interfaces due to small incident angle

-  measurement of intensity g loss of information

9 modeling the sample + fit to match experiments

BornAgain software to simulate and fit GISAS data [2]

Solution

Layers

Multilayered structure with roughness

Si SiO2

Au

Cu

Planar layouts of particles Deposited or embedded particles in layers

Input beam with wavelength divergence

Ag

Si Al2O3