6. Conclusions

We have attempted to show that X-rays used under grazing incidence can be used to characterize surfaces and interfaces, and to measure layer thicknesses or the period of multilayers. The methods described are applicable to a wide variety of materials, both amorphous and crystalline. The same type of instrument can also be used to study the degree of crystallization and the chemical composition of the various phases present. In principle, the basic device is similar to conventional X-ray tube spectrogoniometers, but the system must be adapted to work under grazing incidence, which requires careful rotation, orientation and alignment. For detection, it is often advantageous to use a detector with linear localization, which can avoid scanning the spectrum by simultaneously collecting diffracted, scattered or fluorescent photons at different angles. This type of detector records diffracted...