MSA ROEBLING MEDAL LECTURE- FROM MINERAL PHYSICS TO NANOGEOSCIENCE AND BACK AGAIN

I am deeply honored to receive the Roebling Medal and this lecture summarizes some themes of work I and my group have done, are doing, and hope to continue doing. Thermodynamics and structural chemistry go hand in hand, as do mineralogy and physical chemistry. Starting with ordinary spinels and moving to deep mantle phases, I have identified reasons for high pressure phase transitions, exploring the competition among energetic, volumetric, and entropic factors as composition changes. A balance and synergy between Earth and materials science questions and apporoaches has enriched my work, both intellectually and moneywise. I gradually moved toward the Earth's surface, studyng more complex and hydrated minerals such as zeolites, clays, and iron oxides.There surface effects dominate and their influence defines the new field of nanogeoscience. But surface and interfacial effects are important at depth as well, and I am now thinking of their role in grain boundaries, amorphization, and phases near and in the core, as well as in a planetary context.