Treffer: Novel Materials Simulation Techniques to Investigate Earth’s Interior

Understanding the dynamics and structure of Earth's interior requires investigating the thermodynamic and elastic properties of minerals under extreme pressure and temperature. Experimental methods face significant challenges in reproducing these conditions, requiring alternative methods to study deep Earth materials. Computational simulations, particularly 𝘢𝘣 𝘪𝘯𝘪𝘵𝘪𝘰 methods, offer a powerful way to explore mineral behavior under such conditions but often face limitations due to complex physical effects. To address these challenges, we develop advanced methodologies and novel simulation techniques to study the minerals in the lower mantle and Earth's deepest regions. We use 𝘢𝘣 𝘪𝘯𝘪𝘵𝘪𝘰 computations for 𝜖-Fe under exoplanetary conditions, accounting for electronic thermal excitation effects within the phonon gas model framework. We extend this framework into an open-source Python code for calculating free energy in complicated systems. We investigate pressure-induced changes on the electronic structure of iron in ferropericlase, a spin state change, on the seismological properties of the lower mantle. We further explore ferrous iron partitioning combined with spin crossover and non-ideal solid solution models, to understand major mineral phases in the lower mantle, and their impacts on lower mantle velocities and temperature-induced heterogeneities. We also analyze the impact of Fe and Al alloying on the bridgmanite-post-perovskite phase boundary. Together, these investigations enhance our understanding of the thermal and chemical structure of Earth's deep interior.