For investigations of the crystallographic structure of thin film materials, various diffractometers (Bruker-AXS D8 Advance, Rigaku SmartLab 5) are available. During the measurement the sample is irradiated with monochromatic X-ray and the diffraction pattern of this radiation by the crystal lattice is detected. This method enables a non-destructive structural investigation of the samples providing information on the lattice spacing, grain size and the stress state.