Structure, properties and high-pressure and high-temperature behaviour of iron oxides with implications for the structure and dynamics of the Earth`s lower mantle and core

• Applicant: Privatdozentin Dr. Catherine McCammon
• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: from 2003 to 2007
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5410914

The structure, properties and high-pressure and high-temperature behaviour of FeO, Fe3O4 and Fe2O3 remain controversial, despite several decades of research. Their importance to the geosciences as potential phases during the Earth´s accretion as well as components of present day mantle phases motivates a new examination of their properties and phase diagrams at high pressures and temperatures. Using a newly developed system for resistive heating in the diamond anvil cell and our laser heating facility, samples will be studied using a large range of complementary techniques (Mössbauer, Raman and infrared spectroscopies, X-ray diffraction, and electrical resistivity measurements). Preliminary experiments using the newly developed apparatus have confirmed that experimental challenges such as pressure gradients and sluggish kinetics can be successfully overcome, enabling the goal of identifiying the structure and electronic properties of the high-pressure phases of FeO, Fe3O4 and Fe2O3 that are stable at the pressure and temperature conditions of the Earth´s lower mantle to be realised.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Leonid Dubrovinsky