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arXiv · 1712.01584

Peculiarities of the electronic transport in half-metallic Co-based Heusler alloys

V. V. Marchenkov·Yu. A. Perevozchikova·N. I. Kourov·V. Yu. Irkhin·M. Eisterer·T. Gao
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Abstract

Electrical, magnetic and galvanomagnetic properties of half-metallic Heusler alloys of Co$_2$YZ (Y = Ti, V, Cr, Mn, Fe, Ni, and Z = Al, Si, Ga, Ge, In, Sn, Sb) were studied in the temperature range 4.2--900 K and in magnetic fields of up to 100 kOe. It was found that varying Y in affects strongly the electric resistivity and its temperature dependence $ρ(T)$, while this effect is not observed upon changing Z. When Y is varied, extrema (maximum or minimum) are observed in $ρ(T)$ near the Curie temperature $T_C$. At $T < T_C$, the $ρ(T)$ behavior can be ascribed to a change in electronic energy spectrum near the Fermi level. The coefficients of the normal and anomalous Hall effect were determined. It was shown that the latter coefficient, $R_S$, is related to the residual resistivity $ρ_0$ by a power law $R_S \sim ρ_0^k/M_S$ with $M_S$ the spontaneous magnetization. The exponent $k$ was found to be 1.8 for Co$_2$FeZ alloys, which is typical for asymmetric scattering mechanisms, and 2.9 for Co$_2$YAl alloys, which indicates an additional contribution to the anomalous Hall effect. The temperature dependence of resistivity at low temperatures is analyzed and discussed in the framework of the two-magnon scattering theory.

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V. V. Marchenkov, Yu. A. Perevozchikova, N. I. Kourov, V. Yu. Irkhin, M. Eisterer, T. Gao. 2017-12-05. Peculiarities of the electronic transport in half-metallic Co-based Heusler alloys. https://doi.org/10.1016/j.jmmm.2017.11.019

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