X-ray diffraction XRD

X-ray diffraction (XRD) is a versatile technique for investigating the structure of crystalline materials. Grain sizes, textures and internal stresses can be detected in addition to determining crystallographic phases. The investigation can be conducted on both flat and curved component surfaces. The characterization of thin films (micrometer to nanometre) is a Fraunhofer IST speciality.

XRD phase analysis

XRD-Phasenanalyse. Diffraktogramme von Pb-Zr-Titanat-Schichten, hergestellt mit unterschiedlichen Prozessparametern, gemessen im streifenden Einfall.
© Fraunhofer IST

Diffractograms of Pb-Zr-titanate films, produced with different process parameters, measured with grazing incidence.

XRD grain size determination

XRD grain size determination
© Fraunhofer IST

Spatially resolved determination of the grain sizes in a polycrystalline diamond film. The measurement was taken with a spatial resolution of 1 mm over a distance of 10 mm. In doing so, the respective grain sizes were determined separately for crystals with different orientations where the (111), (220), (311) or (331) lattice planes are parallel to the specimen surface.

XRD internal stress analysis

XRD internal stress analysis
© Fraunhofer IST

For the internal stress analysis, the specimen is generally tilted perpendicular to the beam path so that differently stretched or compressed lattice planes are captured. The stress of the film can be determined from the resulting shift of the diffraction reflexes. Example: Internal stress of 2.6 GPa measured on a PVD-CrN film (thickness approx. 20 µm). Internal stresses can also be determined with grazing incidence using a special process. This allows very thin surface films to be characterized as well.