X-ray diffractometer

• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: Funded in 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 453942554

The Soil Mineralogy Group at the Gottfried Wilhelm Leibniz University Hannover is concerned in research and teaching with the identification and quantification of soil minerals, their structure and physicochemical properties, processes of mineral formation and transformation, and the physicochemical interactions between soil minerals and their environment. For this field of research, the qualitative and quantitative investigation of the phase composition of soils and polymineralic laboratory samples using X-ray diffraction is essential. The investigation of the mineralogical composition of soils requires fast, high-resolution detector systems due to the high number of samples to be analyzed. Clay mineralogical in-situ investigations using oriented clay mounts require the use of reaction chambers in which the temperature can be precisely adjusted up to approx. 600°C and in which the atmospheric composition can be varied. The latter is essential for the analysis of redox-sensitive mineral samples. In addition to conventional X-ray diffraction investigations of mineral samples in reflection mode, capillary measurements (e.g. glass, polyimide) are required for the analysis of small sample quantities, which are typical for many laboratory experiments. The investigation of the structure of soil minerals, in turn, requires the use of different types of X-ray radiation (Cu Ka, Cu Ka1, Mo Ka). Copper Ka radiation is used for conventional reflection-mode measurements, Cu Ka1 radiation for high-resolution X-ray diffraction analysis, especially of poorly crystalline mineral phases, and Mo Ka radiation for capillary measurements as well as the structure elucidation of X-ray amorphous inorganic soil substances by means of pair distribution function (PDF) analysis. At present, there is no X-ray diffractometer of the necessary performance class available at the Institute of Mineralogy of the Gottfried Wilhelm Leibniz University Hannover, so that for the described research a new instrument is needed for the main applicant of this proposal.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Röntgendiffraktometer
• Instrumentation Group: 4011 Pulverdiffraktometer
• Applicant Institution: Gottfried Wilhelm Leibniz Universität Hannover
• Leader: Professor Dr. Christian Mikutta