I obtained in 2020 a PhD in Materials Engineering at Clausthal University of Technology with a thesis investigating the crystallization sequence of lithium magnesium aluminosilicate glasses, performed in cooperation with the glass-producing company Schott AG. In the following years, I worked as a postdoctoral researcher at Clausthal University of Technology (DE) and, as recipient of the DFG Walter Benjamin fellowship, at CNRS CEMHTI in Orléans (FR) and FAU University in Erlangen (DE). My research revolves around the fundamentals of glass formation, phase separation and crystallization in (alumino)silicate melts, with a focus on understanding the role of transition metals and nucleating agents. Moreover, I have a strong interest for the crystallographic analysis of stuffed derivative of SiO2 obtained by the glass crystallization route, such as quartz solid solutions.

Walking a fine line: glass formation vs. seed formation in TiO2-containing (alumino)silicate melts

TiO2 is a widespread and long-standing component of technologically relevant (alumino)silicate melts and glasses. Indeed, this transition metal oxide is key to the production of low-expansion SiO2-TiO2 glasses, but also to the achievement of volume nucleation in a variety of glass-ceramics due to its remarkable efficiency as seed former. However, investigating the metastable (micro)structural evolution of TiO2-containing melts with sufficient spatial and temporal resolution has so far proved challenging, preventing the development of an overarching mechanistic understanding of such contrasting behaviour across different compositional systems.
In this talk, recent experimental results are combined to elucidate some crucial factors controlling the incorporation of TiO2 into the amorphous structure of silicate melts or its precipitation in the form of nanocrystals. The complex interplay of melt solubility, nanoscale chemical diffusion, non-stoichiometric nucleation and Ostwald´s rule of stages will be discussed with a focus on SiO2-TiO2 and TiO2-doped aluminosilicate systems such as Li2O-Al2O3-SiO2, MgO-Al2O3-SiO2 and ZnO-Al2O3-SiO2, as well as multicomponent geological melts.