Open AccessComment on ‘High‐pressure polymorphism of FeO? An alternative interpretation and its implications for the Earth's core’ by L. Liu, P. Shen and W. A. Bassett
Author(s) -
Jackson Ian,
Ringwood A. E.,
McCammon C. A.
Publication year - 1984
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1984.tb01935.x
Subject(s) - wüstite , magnetite , shock (circulatory) , thermodynamics , phase (matter) , interpretation (philosophy) , high pressure , compression (physics) , materials science , geology , metallurgy , physics , computer science , quantum mechanics , medicine , programming language
Summary. Published shock compression data for wüstite (Fe 0.94 O) have been variously interpreted in terms of either an essentially first‐order phase transformation, or progressive exsolution of iron leaving increasingly non‐stoichiometric wüstite with a composition ultimately approaching Fe 0.75 O (i.e. Fe 3 O 4 ). Equation of state parameters for the hypothetical Fe 0.75 O wüstite phase, upon which the latter interpretation is based, are shown to be grossly inconsistent with existing shock compression data for magnetite (Fe 3 O 4 ). It is concluded that progressive exsolution of iron cannot account for the high densities of wüstite shocked beyond 70GPa.