Wendy Li-Wen Mao Graduate Student Department of the Geophysical Sciences 5734 S. Ellis Ave. HGS 531 Chicago, IL 60637 USA Tel: (773) 955-4040, ext. 5-6697 E-mail: wmao@uchicago.edu Personal Website (includes C.V. and publication list. Please email for PDF files of publications.)

My main research interest is the study of materials under high pressure, where there is a wealth of new phases and phenomena to be investigated.  One major research topic has been studying crystalline phases in simple molecular systems (e.g. H₂-H₂O and H₂-CH₄) using Raman and infrared spectroscopies and x-ray and neutron diffraction. We have discovered new van der Waals compounds and found increased stability to near ambient pressure at low temperature with possible planetary science relevance and application for hydrogen storage.

My thesis work is on the geophysics of iron at core conditions. I am also investigating possible core-mantle interactions by studying Fe-rich silicates under D” conditions. By far the major fraction of minerals in the Earth is hidden at great depth under pressures.  They control the formation, the evolution, the present state, and the destination of the solid Earth. Recent studies of the Earth's deep interior present us with a rich array of large-scale processes and phenomena that are not fully understood. Resolving these questions requires a detailed understanding of the physics and chemistry of the relevant materials at high pressures and temperatures.

The sample environments required by these experiments (mainly in a diamond anvil cell), however, has limited the measurements possible by conventional probes. Synchrotron radiation has enabled a wide variety of novel techniques for characterizing materials at extreme conditions. I have used inelastic x-ray scattering (x-ray Raman) to study the near K-edge structure of carbon at high pressure, a flux-limited experiment only possible at a third generation synchrotron facility like the Advanced Photon Source. This resulting work finally solved the mystery of what happens to cold-compressed graphite, a problem that had puzzled scientists for nearly four decades, because the appropriate measurements were not possible. I am also working on utilizing CVD diamonds for ultrahigh pressure experiments.