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
European Journal of Mineralogy Volume 13 Number 5 (2001), p. 857 - 861
published: Sep 27, 2001
Abstract
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.
Keywords
magnesiowustite • high pressure • immiscibility • earth's lower mantle • diamond-anvil cell