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Title: Thermal conductivity of liquid iron alloy at core-mantle boundary conditions
Plain: How well molten iron conducts heat under core pressures controls how much heat is left to stir the core. Calculations and lab experiments disagree by a large factor.
Precise: Determine the thermal conductivity $k$ of the outer-core Fe-Ni-light-element liquid at $P \sim 1.36e12\,\mathrm{dyn}/\mathrm{cm}^2$ and $T \sim 4000\,\mathrm{K}$. Ab initio calculations give $k$ of order $1e7\ \text{to}\ 2.5e7\,\mathrm{erg}/(\mathrm{s}\,\mathrm{cm}\,\mathrm{K})$ while some laser-heated diamond-anvil measurements give values near $3e6\,\mathrm{erg}/(\mathrm{s}\,\mathrm{cm}\,\mathrm{K})$. An answer is $k$ with about 20 percent uncertainty including light-element and electron-electron scattering contributions.
Settled by: Concordant dynamic or static high-pressure transport measurements at core conditions and ab initio calculations including electron-electron scattering.
Kind: well-posed
Answer type: value
References: (empty)
Literature status: contested
Status note: Experiment-theory disagreement persists as of 2024 to 2025, with new calculations for Fe-H and Fe-Si alloys (e.g. arXiv:2408.04521).
Posed since: (empty)