Figure 5 : Iron/nickel alloy under pressure.

From: Local magnetic moments in iron and nickel at ambient and Earth’s core conditions

Figure 5

(a) DOS of the ɛ (hcp) phase of iron at ambient and Earth’s core pressure (green and blue lines, respectively). E=0 corresponds to the chemical potential of hcp iron. The vertical dashed lines indicate the energies at which the local levels of Ni and Mn are shifted within the CPA+DMFT scheme. In contrast to the shift for the Fe/Mn alloy (used here as a reference example), that for Fe/Ni brings the local levels of nickel close to the peak at the top of the hcp band. Since the latter is similar to the sharp features of pure fcc nickel (shown in Fig. 4a), the non-Fermi-liquid effects observed in the pure fcc material are expected to survive in the iron/nickel alloy. (b) Non-interacting local spin susceptibility for pure hcp iron and for the alloys of hcp iron with Mn and Ni, all at Earth’s core pressure, that is, 330 GPa. The iron/nickel alloy strongly deviates from standard Pauli behaviour of good Fermi liquids. The example of Mn is on the contrary much closer to the Fermi-liquid result of hcp iron. (c) The scattering rate (averaged over all d orbitals) of the nickel alloy at high temperatures within CPA+DMFT is remarkably similar to the corresponding one of pure fcc nickel at these pressures and much larger than that of the Fe/Mn alloy, taken here as a reference.