Report

Reduced Radiative Conductivity of Low-Spin (Mg,Fe)O in the Lower Mantle

See allHide authors and affiliations

Science  26 May 2006:
Vol. 312, Issue 5777, pp. 1205-1208
DOI: 10.1126/science.1125622

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Abstract

Optical absorption spectra have been measured at pressures up to 80 gigapascals (GPa) for the lower-mantle oxide magnesiowüstite (Mg,Fe)O. Upon reaching the high-spin to low-spin transition of Fe2+ at about 60 GPa, we observed enhanced absorption in the mid- and near-infrared spectral range, whereas absorption in the visible-ultraviolet was reduced. The observed changes in absorption are in contrast to prediction and are attributed to d-d orbital charge transfer in the Fe2+ ion. The results indicate that low-spin (Mg,Fe)O will exhibit lower radiative thermal conductivity than high-spin (Mg,Fe)O, which needs to be considered in future geodynamic models of convection and plume stabilization in the lower mantle.

    View Full Text