Original paper

Stability of (Mg0.5Fe0.5)O and (Mg0.8Fe0.2)O magnesiowustites in the lower mantle

Dubrovinsky, Leonid; Dubrovinskaia, Natalia; Annersten, Hans; Hålenius, Elke; Harryson, Hans


We have heated magnesiowüstites (Mg0.5Fe0.5)O and (Mg0.8Fe0.2)O to temperatures of over 1000 K at pressures of over 80 GPa simulating the stability of the solid solution at physical conditions relevant to the Earth's lower mantle. The X-ray study of the externally heated samples in diamond-anvil cells shows that magnesiowüstite may dissociate into a magnesium-rich and an iron-rich oxide component. The result is important because the decomposition of magnesiowüstite into lighter and heavier phases will cause dynamic effects that could lead to mantle heterogeneity.


magnesiowustitehigh pressureimmiscibilityearth's lower mantlediamond-anvil cell