Application of phase-field simulation of solidification and texture evolution to diffusion chronometry

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The aim of the project is to initiate a quantitative understanding of the growth mechanisms and texture formation during the growth and dissolution of crystals in melt bearing systems. This is of particular interest for the applications of Diffusion Chronometry to magmatic systems, where the process of textural maturation involving growth and dissolution of crystals and associated changes in crystal shapes lead to modification of diffusion profiles. The phase-field modeling method, which is an efficient, thermodynamically consistent tool for modeling complex diffusion and growth phenomena, will be used. An effective multicomponent multi-phase-field approach will be coupled to the methods for anisotropic diffusion and anisotropic faceted crystal growth. A model olivine-melt system has been chosen for this preliminary study. Textural evolutions based on estimated values of surface energy and thermodynamic parameters will be studied and compared to results from experiments. A particular goal of the research project is the investigation of the effect of texture and crystal shape evolution by crystal growth/dissolution on the lifetime of a particular crystal in a magmatic environment. The developed approach will help to define the upper limits of timescales accessible by diffusion chronometry. Anisotropic multicomponent phase-field modeling of growth/dissolution processes also provides a foundation for reliable predictions of microstructure and texture evolution in related material systems.