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Temperature-dependent resistivity and anomalous Hall effect in NiMnSb from first principles

Publication at Faculty of Mathematics and Physics |
2019

Abstract

We present implementation of the alloy analogy model within fully relativistic density-functional theory with the coherent potential approximation for a treatment of nonzero temperatures. We calculate contributions of phonons and magnetic and chemical disorder to the temperature-dependent resistivity, anomalous Hall conductivity (AHC), and spin-resolved conductivity in ferromagnetic half-Heusler NiMnSb.

Our electrical transport calculations with combined scattering effects agree well with experimental literature for Ni-rich NiMnSb with 1-2% Ni impurities on Mn sublattice. The calculated AHC is dominated by the Fermi surface term in the Kubo-Bastin formula.

Moreover, the AHC as a function of longitudinal conductivity consists of two linear parts in the Ni-rich alloy, while it is nonmonotonic for Mn impurities. We obtain the spin polarization of the electrical current P > 90% at room temperature and we show that P may be tuned by chemical composition.

The presented results demonstrate the applicability of an efficient first-principles scheme to calculate temperature dependence of linear transport coefficients in multisublattice bulk magnetic alloys.