Transport properties of iron under Earth's core conditions

Transport properties of iron in Earth's core control the dynamo that generates Earth's magnetic field. If the thermal conductivity is high, heat transport is through conduction, and if low by convection. Conventional dynamo theory considered thermal convection primarily to drive the dynamo, but it is also possible to sustain a dynamo through chemical segregation, such as growth of Earth's inner core. We computed the electrical resistivity and thermal conductivity of solid and liquid iron under core conditions, including both electron-ion (electron-phonon) and electron-electron scattering (Xu et al., PRL 121 096601, 2018). We have included saturation effects in different approximations. We find somewhat higher resistivity than recent resistivity measurements and somewhat higher thermal conductivity than recent thermal conductivity measurements. Thermal conductivities are lower than would be obtained using an ideal Wiedemann-Franz Lorenz factor. Electron-electron scattering also decreases the thermal conductivity. Our results are consistent with a convection driven dynamo.