Publications in Scientific Journals:
V. Drchal, J. Kudrnovsky, D. Wagenknecht, I. Turek, S. Khmelevskyi:
"Transport properties of iron at Earth's core conditions: The effect of spin disorder";
Physical Review B,
The electronic and thermal transport properties of the Earth´s core are crucial for many geophysical models
such as the geodynamo model of the Earth´s magnetic field and of its reversals. Here we show, by considering
bcc iron and an iron-rich iron-silicon alloy as a representative of the Earth´s core composition and applying
first-principles modeling, that the spin disorder at the Earth´s core conditions not considered previously provides
an essential contribution, of order 20 μ cm, to the electrical resistivity. This value is comparable in magnitude
with the electron-phonon and with the recently estimated electron-electron scattering contributions. The origin
of the spin-disorder resistivity (SDR) consists of the existence of fluctuating local moments that are stabilized at
high temperatures by the magnetic entropy even at pressures at which the ground state of iron is nonmagnetic.
We find that electron-phonon and SDR contributions are not additive at high temperatures. We thus observe a
large violation of the Matthiessen rule, not common in conventional metallic alloys at ambient conditions.
Created from the Publication Database of the Vienna University of Technology.