Research Interests

My research focuses on the properties of materials at the high pressures and temperatures existing deep inside planets, the objective being to characterize the processes by which planets evolve over geological time periods. Most of my research is experimental, using both static (diamond-anvil cell) and dynamic (shock-wave) methods, and is intended to document the phases (e. g., crystal structures) produced at high pressures, and the elastic, thermal and electronic properties of these phases. The high-pressure measurements have also been used to successfully test and improve theoretical predictions of material properties based on first-principles (quantum mechanical) calculations. Elements and compounds typically exhibit dramatic changes in chemical-bonding upon compression to the ~ million atmosphere pressures achieved within planets (e. g., electrically insulating salts becoming metallic); the material properties of deep planetary interiors thus differ significantly from the properties of those same materials at Earth-surface conditions. Recent work combines shock-wave and static techniques in order to extend experiments from the million-atmosphere to the billion-atmosphere range of pressures: high enough to reproduce conditions inside super-giant planets and brown dwarfs, and to explore an entirely new regime of chemical bonding ("kilovolt chemistry").

Membership Type

Member

Election Year

2004

Primary Section

Section 15: Geology

Secondary Section

Section 16: Geophysics