X-ray diffraction is an analytical method with a wide field of applications. The basic principle behind all investigations is the solution of Bragg's equation, 2 d sin W = n*k.(1)When energy-dispersive X-ray diffraction is used, the Bragg angle (W) can be kept constant during measurements, since the value of the lattice plane distance (d) in Bragg's equation is determined experimentally by determination of the wave-length (k) of the diffracted beams of the original polychromatic radiation [1,2]. Figure 1 demonstrates the difference between conventional (angle-dispersive) diffraction and energy-dispersive diffraction.In the case of energy-dispersive diffraction, in contrast to conventional diffraction, a goniometer for the exact measurement of different diffraction angles is not necessary [3,4]. Combining this advantage with small power X-ray tubes, appropriate X-ray optics for the primary and the diffracted beam in conjunction with high energy-resolution detectors, small and transportable measurement equipment can be constructed, which permits a mobile use and which is especially convenient for process analysis applications [5]. Comparison with Conventional DiffractometryUsing a suitable set-up for energy-dispersive diffraction, results of the same quality as compared to angle-dispersive diffraction can be achieved. The investigation of sheets, powders, ingots, wires, coins and pills has been proved successfully. Measurements on different diamond-deposited substrates have shown that, also for samples with complex crystalline structures, no significant differences between measured and predicted values occur (Figure 2).The following example illustrates that also difficult problems may be solved by applying this technique: The investigation of soldered Cu-PCBs shows that intermetallic phases on the Cu-tracks are created during tempering which can be identified subsequently (Figure 3). AbstractThe important advantage of energy-dispersive X-ray diffraction is the opportunity to obtain diffraction patterns without the use of any goniometer. Thus, a combination of small power X-ray tubes, appropriate X-ray optics and high energy-resolution detectors enables the construction of small and transportable measurement de-vices also for mobile use. Specimens of different size, shape, and geometry can be investigated. In this article, the application of energy-dispersive X-ray diffraction on polycrystalline materials is demonstrated and examples in the fields of micro system technologies, deposition techniques and quality control are presented.

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Internal stresses are very important for the performance of protective hard coatings. Tensile stresses favour the formation and propagation of cracks, inducing fracture and corrosion. Medium compressive stresses hinder fatigue. But high compressive stresses, typically for hard coatings produced by PVD (physical vapour deposition) processes, support delamination in order to relax the stored elastic energy. However notwithstanding its relevance, the internal stresses are only seldom used for the optimisation and quality control of hard coatings in industry. This unsatisfying situation is caused by the deficit in efficient measuring methods. The results of thin sheets, where the stresses can be simply measured by their curvature, are not necessarily representative for the coating of thicker parts. The conventional XRD (X-ray Diffraction), based on angle-dispersive evaluation needs expensive devices and is rather time consuming. The energy-dispersive technique opens new possibilities. It is based on polychromatic radiation. The interference of the lattice plane reflections corresponding to the Bragg-equation is investigated by the diffraction intensity of the different wavelength (or photon energies), not by varying the Bragg-angle as in conventional XRD. Hence, the whole diffraction pattern can be obtained in one shoot without the use of any goniometer. This allows the construction of small and compact measuring devices and the reduction of measuring time to a few minutes. The capability of the ED-XRD (Energy Dispersive X-ray Diffraction) is demonstrated for titanium nitride and chromium nitride films deposited by cathodic vacuum arc with varying parameters. Comparisons were made with the much more time-consuming AD-XRD (Angle Dispersive X-ray Diffraction) for residual stress analysis. The results of both methods are in good agreement.