Uploaded December 2022 | Updated September 2026, 2 weeks ago
Innocent Ezenwa, a postdoc at the Carnegie Institution for Science, presented, Melting Curve of Fe at High-Pressure by Inter-Metallic Fast Diffusion Technique" at AGU 2022.
Abstract: The planetary core is mostly Iron (Fe) in composition. The melting temperature of Fe at the inner core boundary constrains the thermal structure and the solidification of the planetary core. However, the high-pressure melting curve of Fe is ill constrained. It is generally known that diffusion in disordered materials is faster than in the respective crystalline phases. Hence, a change in the diffusion behavior can be used as a criterion to detect melting at a given pressure. Here, we present a new method in multi-anvil press to precisely determine the melting temperature of Fe by characterizing the interaction between Fe-W boundary layer. Using this technique, we measured the melting temperature of Fe at various fixed pressures between 8-21 GPa. Our new data place an upper bound in the assessment of the temperature at the inner core boundary of the small planetary bodies. The melting curve established in our investigation could also serve as an anchor point for the extrapolation of Fe melting curve to higher pressure. We further assessed the melting curve of fcc(γ)-Fe up to the triple point in light of our new measurements.
More info: https://epl.carnegiescience.edu/epl-agu22
Innocent Ezenwa, a postdoc at the Carnegie Institution for Science, presented, Melting Curve of Fe at High-Pressure by Inter-Metallic Fast Diffusion Technique" at AGU 2022.
Abstract: The planetary core is mostly Iron (Fe) in composition. The melting temperature of Fe at the inner core boundary constrains the thermal structure and the solidification of the planetary core. However, the high-pressure melting curve of Fe is ill constrained. It is generally known that diffusion in disordered materials is faster than in the respective crystalline phases. Hence, a change in the diffusion behavior can be used as a criterion to detect melting at a given pressure. Here, we present a new method in multi-anvil press to precisely determine the melting temperature of Fe by characterizing the interaction between Fe-W boundary layer. Using this technique, we measured the melting temperature of Fe at various fixed pressures between 8-21 GPa. Our new data place an upper bound in the assessment of the temperature at the inner core boundary of the small planetary bodies. The melting curve established in our investigation could also serve as an anchor point for the extrapolation of Fe melting curve to higher pressure. We further assessed the melting curve of fcc(γ)-Fe up to the triple point in light of our new measurements.
More info: https://epl.carnegiescience.edu/epl-agu22
