I joined the High Pressure Group at LLNL in 1998, after getting my Ph.D. in Physics from University at Buffalo –SUNY. Since then, I have been involved in materials research at high pressure (diamond anvil cell) using a wide rage of experimental probes from optical measurements to x-ray diffraction and spectroscopy.

My current research explores the physics and chemistry of materials over a broad range of pressure-temperature conditions, with emphasis on the relationship between structural phase stability, chemical bonding, and electronic structure in highly compressed systems.

One area of particular interest involves the bonding changes of molecular solids under extreme thermodynamic conditions. The morphology and mechanical properties of molecular systems are largely controlled by the large disparity between strong intra-molecular bonds and relatively weak inter-molecular cohesive forces. In highly compressed molecular systems, however, this intra/inter molecular bonding hierarchy becomes less differentiated, and the materials eventually transform to covalent, ionic or metallic solids. One example is that of carbon dioxide undergoing a sequence of bonding changes with pressure from a simple molecular solid to a series of highly interacting (associated) phases and eventually to a fully covalent, tetrahedrally coordinated solid.

A second area of interest has been the complex relationship between atomic structure and electronic properties in magnetic transition metals at pressures reaching Earth Core conditions. Beyond its applications to Geomagnetism and Planetary Physics, this research advances our fundamental understanding of spin polarization and ordered magnetism in itinerant electron systems.