A New Approach for Getting Refined X-Ray Diffraction Patterns by Using X-Ray Diffractometers with Energy Resolving Detectors

摘要

The known X-ray diffraction methods yield diffraction patterns as convolution of the sample characteristics with the device function (spectral distribution of the primary radiation inclusive influences of filters or monochromators, geometric characteristics of the goniometer as well as detector properties). For evaluation of X-ray diffraction patterns the device function is usually described by mathematical models which can base on measurements of known samples. We present a new approach for getting X-ray diffraction patterns in the angle dispersive mode by using energy resolving detectors. The main idea is to use all information contained in the energy spectra. That means more than only increasing of the peak to background ratio by differential discrimination. The approach allows the utilization of the whole elastically scattered radiation (no intensity losses caused by monochromators or filters) and the elimination of contributions of device function, inelastically scattered and fluorescence radiation. By that way the time needed for measuring a X-ray diffraction pattern can be decreased significantly if a suitable detector is available. The most important aspect is that one can get reflection profiles which are determined only by the real structure of the sample. The mathematical approach is based on the numerical comparison of the complete energy spectrum measured for an interesting sample at every angle step with a set of standard energy spectra got for a standard sample (known influences of real structure) with comparable geometric conditions. The mathematics and experimental prerequisites are described.