ROEBLING MEDAL | THE STABILITY OF MINERALS: AN ATOMISTIC PERSPECTIVE

The factors that control the stability of minerals have been a common theme throughout my career. Specifically, I have explored the relationship between the atomic-scale properties of a phase and its bulk thermodynamic properties. For example, enthalpy is related to bond strengths derived from bond valence theory and quantum mechanical calculations, entropy is related to lattice vibrations and order/ disorder effects, volumes are related to crystal structures and their response to pressure and temperature conditions defining their equations of state. To achieve this goal, I have used a combination of theoretical modelling with experimental techniques including calorimetry, X-ray and neutron diffraction, infrared, Raman and inelastic neutron spectroscopy and phase equilibria studies. I have conducted experiments under different pressure-temperature conditions that are suitable for probing the Earth's interior from the crust to the lower mantle. In this presentation, I review examples of oxides, hydroxides, carbonates, borates, phosphates, silicates, selenides and sulfides and how their crystal structures control their physical, elastic and thermodynamic properties. These studies have been extended to include the structure / property relations of hybrid materials that provide new insights into chemical bonding. Looking to the future, I discuss how mineral structures provide the inspiration for the materials of the future.