Fluorescence is commonly a problem in mineralogical phases like Hematite- Eskolaite, because these minerals contain the strongly fluorescing Cr and Fe ions. This data sheet shows how the 1Der detector excludes both Cr and Fe fluorescence. Empyrean’s unique optical configuration provides truly clean data leading to an excellent Rietveld refinement and resulting in an accurate crystal structure determination of this natural mineral.
For X-ray diffraction (XRD) measurements on the Empyrean system, it is beneficial to be able to choose an X-ray tube to suit the requirements of a material. Standard Empyrean tubes offer a choice of Cr, Mn, Fe, Co, Cu, Mo and Ag, and other anode emission energies can be provided on request. Cu is the most commonly used anode and the Cu Kα emission peak is the most commonly used energy for diffraction experiments.
In an X-ray diffraction experiment, the optics and the detector are together tuned to the narrow energy window required by the experiment. The 1Der strip detector can be automatically tuned to provide a narrow energy window around any chosen diffraction energy. This provides full flexibility across the whole range of Empyrean 1D applications.
All elements fluoresce when irradiated with a certain X-ray energy. In a diffraction measurement, fluorescence from some elements can give rise to unwanted background intensity in a diffraction pattern. A high background reduces the possibility of identifying the low intensity peaks that often provide the final clues in a Rietveld crystal structure refinement. Figure 1 illustrates the elements that emit the greatest fluorescence interference in a diffraction measurement using a Cu X-ray tube. There are various strategies for excluding fluorescence interference and, in this datasheet, we show how the 1Der detector address the double challenge of fluorescence from both Cr and Fe elements.