Coplanar grazing exit X-ray diffraction on thin polycrystalline films

X-ray powder diffraction analysis in the coplanar grazing exit (GE) parallel beam geometry was tested on thin polycrystalline TiO(2) films with the aid of a laboratory diffractometer. Peak position, width and intensity were simulated by a model accounting for the effects of refraction, scattering in the layered sample, absorption and instrumental effects related to the grazing exit geometry. A model of absorption-induced peak broadening close to the critical angle was created. Measured data for a series of samples with different thicknesses were successfully fitted by the model. It is shown that the grazing exit coplanar diffraction is a suitable technique for thin films analysis in particular because of its flexible spatial and angular resolution.