Effect of defect clustering on the high-pressure behaviour of wustite. High-pressure X-ray diffraction and lattice energy simulations

The effect of pressure on the defect structure and phase relations of wusti te, Fe1-xO, has been studied by high-pressure X-ray diffraction and lattice energy simulations. Both the experiments and the simulations suggest that the bulk modulus of wustite does not vary significantly with composition, a nd moreover does not seem to depend on the defect structure of the compound . Thermodynamic modeling using a composition independent bulk modulus of 15 0 GPa suggests a significant widening of the stability field of wustite rel ative to iron and magnetite at high pressure. This conclusion is in general agreement with the increased binding energy of defect clusters in wustite at high pressure.