Working group Mineralogy and Geochemistry

The research of my working group aims at understanding the mechanisms, thermodynamics, and kinetics of mineral alteration or replacement processes in aqueous solutions, but also in melts. Thereby, the focus is on materials that have been used and are proposed to immobilize high-level radioactive waste and, more recently, on biomaterials to better understand fossilization processes. My research projects involve the synthesis, structural characterization, and, in particular, the experimental corrosion of borosilicate glasses and ceramic materials in aqueous solutions, including self-irradiation-damaged (metamict) materials. Experimental studies are combined with mineralogical and isotope geochemical investigations on naturally altered, partly metamict minerals and rocks. Currently, my group is working intensively on an innovative experimental approach to study solid-water reactions and high-temperature solid-solid and solid-melt reactions in-situ and in-operando, i.e., without having to stop the reaction before analysis. We use confocal Raman spectroscopy in combination with self-developed reaction cells to study the corrosion of silicate glasses (see: https://www.eurekalert.org/pub_releases/2019-02/uob-iii022819.php). By using isotope tracers, the new approach enables the spatially and temporally resolved in-situ investigation and quantification of reaction and transport processes between solid and aqueous solutions and between solid-solid and solid-melt phases in high-temperature ceramic systems.