Grazing Incidence In-plane X-ray Diffraction in the Laboratory

The laboratory implementation of grazing incidence in-plane X-ray diffraction, using an unmodified commercial diffractometer, is described. Low resolution, high intensity measurements are illustrated in the study of the in-plane lattice parameters and texture of a thin polycrystalline ZnO film on glass, the in-plane order in Cd arachidate Langmuir-Blodgett films, and the depth dependence of lattice parameter in graded Si-Ge epilayers. Use of an asymmetrically cut Ge crystal to compress and monochromate the beam provides a high resolution setting, appropria te to measurement of the in-plane mosaic of mismatched epilayers such as GaN on sapphire.