Metallic iron, in both solid and liquid states, is the dominant component of Earth's core. Density measurements of molten iron containing an appropriate amount of light elements (5.7. wt.% carbon) identified a liquid-liquid transition by a significant compressibility increase in the vicinity of the δ-γ-liquid triple point at 5.2. GPa. This transition pressure coincides with a marked change in the pressure evolution of the distributions of nickel, cobalt and tungsten between liquid metal and silicate melt that form a cornerstone of geochemical models of core formation. The identification of a clear link between molten metal polymorphism and metal-silicate element partitioning implies that reliable geochemical core formation models will need to incorporate the effects of these additional liquid metal transitions. © 2011 Elsevier B.V.
Sanloup, C., van Westrenen, W., Dasgupta, R., Maynard-Casely, H., & Perrillat, J. P. (2011). Compressibility change in iron-rich melt and implications for core formation models. Earth and Planetary Science Letters, 2011(306), 118-122. https://doi.org/10.1016/j.epsl.2011.03.039