Stability of Ferropericlase in the Lower Mantle.
We have heated ferropericlases (Mg(0.60)Fe(0.40))O and (Mg(0.50)Fe(0.50))O to temperatures of 1000 kelvin at pressures of 86 gigapascals, simulating the stability of the solid solution at physical conditions relevant to Earth's lower mantle. The in situ x-ray study of the externally heated samples in a Mao-Bell-type diamond anvil cell shows that ferropericlase may dissociate into magnesium-rich and iron-rich oxide components. The result is important because the decomposition of ferropericlase into lighter and heavier phases will cause dynamic effects that could lead to mantle heterogeneity.
Dubrovinsky
LS
Institute of Earth Sciences, Uppsala University, S-752 36 Uppsala, Sweden. European Synchrotron Radiation Facility (ESRF), BP 220, F-38043 Grenoble Cedex, France.
Dubrovinskaia
NA
Saxena
SK
Annersten
H
Hålenius
E
Harryson
H
Tutti
F
Rekhi
S
Le Bihan T