Renewal of an X-ray powder diffractometer for flexible use in diffraction and total scattering

• Subject Area: Chemical Solid State and Surface Research
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 584147295

The X-ray powder diffractometer with two measuring stations, which is to be replaced, was commissioned in 2008 and is no longer adequately equipped to meet the scientific requirements and questions that have changed significantly since then. There is still a need for X-ray powder diffraction as one of the standard analytical methods in solid-state chemistry in order to enable investigations, for example, about the existing crystalline phases, phase proportions, or crystallite sizes. A significant proportion of the substances currently being investigated are disordered, nanocrystalline, or amorphous. This is where classical X-ray diffraction reaches its methodological limits. In addition to Bragg reflections, such samples show significant amounts of diffuse scattering, which also contains structural information. This information can be accessed via total scattering experiments and calculation of the pair distribution function, which allows analysis of structures in real space. These measurements require specially equipped X-ray powder diffractometers, which allow very good data sets to be obtained with this laboratory equipment. The requested renewal essentially comprises a new detector at one measuring station to ensure high signal intensity for the hard radiation currently in use, as well as a refurbishment of the second measuring station for total scattering experiments to calculate the pair distribution function (PDF) and a new X-ray generator. Furthermore, components are included to enable switching between monochromatic molybdenum and silver radiation, which allows adaptation to methodological and analytical requirements. The proposed upgrade will significantly expand the analytical portfolio of the institute for investigating the material chemistry of heterogeneous catalysts. The device will continue to be available for use by all CAU research groups. Potential users are expected to include groups at the institute as well as others in the Faculty of Engineering and the geosciences. Furthermore, the groups bundled in the KiNSIS (Kiel Nano Surface and Interface Science) research focus should also be mentioned. In addition, the device will also be used in teaching to introduce master's students to the pair distribution method at an early stage.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Erneuerung eines Röntgenpulverdiffraktometers für flexiblen Einsatz in Diffraktion und Totalstreuung
• Instrumentation Group: 4011 Pulverdiffraktometer
• Applicant Institution: Christian-Albrechts-Universität zu Kiel
• Leader: Professor Dr. Malte Behrens