bornagain software: simulating and fitting grazing...
TRANSCRIPT
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: [email protected] 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