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X-ray Scattering on Thin Films

Class at Faculty of Mathematics and Physics |
NFPL013

Syllabus

FPL013

1. Experimental aspects of high-resolution x-ray scattering X-ray monochromators and analyzing crystals, reciprocal space maps of scattered intensity, resolution function of a diffractometer, various scattering geometries: coplanar (XRR, XRD), non-coplanar (GISAXS, GID, GICE)

2. Basic description of a wave field An x-ray wave in vacuum, the Green function of a free particle, the Weyl representation, scattering of a wave field, differential scattering cross-section, directions of the waves scattered from a perfect, laterally infinite layer

3. Theory of kinematical scattering from ideal layers Scattering from an ideal small crystal in the Fraunhofer approximation, scattering from a laterally infinite thin layer, x-ray reflection, x-ray diffraction, empirical refraction and absorption corrections

4. Kinematical x-ray scattering from disturbed thin layers Homogeneous deformation, pseudomorph and relaxed layers, periodic superlattices, random deformation, coherent and incoherent (diffuse) scattering

5. Dynamical x-ray scattering Equations for the amplitudes, dispersion surface, boundary conditions at the crystal surface, one-beam approximation, x-ray reflection, two-beam approximation, x-ray diffraction, n-beam diffraction, non-coplanar diffraction, semi-kinematical approximation, method DWBA

6. Measurement of basic structural parameters of thin layers Thickness of a thin layer and multilayer, elastic and plastic deformation in thin layers, determination of the degree of plastic relaxation by x-ray diffraction, study of surface reconstruction by GID

7. X-ray reflection from rough interfaces Statistical model of a rough interface, fractal and non-fractal roughness, growth models of a rough surface, EW and KPZ equations, coherent reflection from rough interfaces, diffuse reflection from rough interfaces

8. Diffuse scattering from volume defects in thin layers Classification of defects, strong and weak defects, diffuse scattering from precipitates, diffuse scattering from dislocations, mosaic structure model

9. X-ray scattering from self-organized structures Mechanisms of a self-organizing growth, a phenomenological model of a self-organized structure, small-angle scattering: XRR, GISAXS, x-ray diffraction: XRD, GID

Annotation

Theoretical description and experimental applications of high-resolution x-ray scattering for structural investigations of single-crystalline thin layers and superlattices. Theoretical background of the method is formulated including the elements of kinematical and dynamical scattering theories and several models of a real structure of a thin single-crystalline layer.

Recent results of small angle x-ray scattering from randomly rough interfaces, x-ray diffraction and diffuse scattering from crystalline thin layers with structure defects and from self-organized quantum dots.