We have carried out high-pressure Raman and (synchrotron-based) infrared spectroscopic studies on a number of materials in recent years. These include IR studies of phases D and E which are dense hydrous magnesium silicates. Phase E may be an important water carrier in subducting slabs and phase D may be a host for hydrogen in the Earth’s lower mantle. In one recent Raman study, we examined the behavior of MgGeO3 perovskite and post-perovskite to pressures above 1 Mbar. Our collaborators in these projects include S. Shieh (U. Western Ontario) and D. Shim (MIT).
Photographs of test samples studied with Raman spectroscopy: (a) NSTX flake and dust particles; (b) carbon soot deposited on the arc cathode; (c post-arc reminder of the graphite anode; (d) a graphite sample heated to about 2000 K in a vacuum furnace. The latter two samples were obtained from an unused graphite tile.