Paper in Press
GEOPHYSICAL RESEARCH LETTERS, doi:10.1029/2011GL049800
Phase transition and metallization of FeO at high pressures and temperatures
- FeO becomes metallic at P-T conditions of the Earth's lower mantle and core.
- This new phase boundary resolves major discrepancies in the FeO phase diagram.
Wüstite, Fe(1-x)O, is an important component in the mineralogy of Earth's lower mantle and may also be a component of the core. Therefore its high pressure-temperature behavior, including its electronic structure, is essential to understanding the nature and evolution of Earth's deep interior. We performed X-ray diffraction and radiometric measurements on wüstite in a laser-heated diamond anvil cell, finding an insulator-metal transition at high pressures and temperatures. Our data show a negative slope for this apparently isostructural phase boundary, which is characterized by a volume decrease and emissivity increase. The metallic phase of FeO is stable at conditions of the lower mantle and core, which has implications for the high P-T character of Fe-O bonds, magnetic field propagation, and lower mantle conductivity.
Received 29 September 2011; accepted 1 November 2011.
Citation: (2011), Phase transition and metallization of FeO at high pressures and temperatures, Geophys. Res. Lett., doi:10.1029/2011GL049800, in press.