Anomalous Hall Effect in Frustrated Magnets

Abstract

Comparative analysis of Hall effect in substitutional solid solutions Ho_0.5Lu_0.5B₁₂, Mn_1 – xFe_xSi (0 ≤ x ≤ 1) and Eu_1 – xGd_xB₆ (x < 0.04) is carried out at temperatures 2–300 K in magnetic fields up to 8 T. Anomalous contribution to the Hall effect \(\rho _{{xy}}^{{\text{A}}}\) ~ \({{\rho }_{{xx}}}M\) has been identified for systems with various types of magnetic frustration. The linear scaling \(\rho _{{xy}}^{{\text{A}}}\) ~ ρ_xx is detected in the resistivity range ρ_xx ~ 0.01–1 mΩ cm lying outside the range of applicability of the classical model of asymmetric scattering. It is associated with the increase in the amplitude of spin fluctuations in the paramagnetic phase of the investigated compounds with noncollinear magnetic structure. The topological contribution to the Hall effect is extracted for Ho_0.5Lu_0.5B₁₂ and Eu_1 – xGd_xB₆. Its amplitude is found to vary from 80 nΩ  cm (Ho_0.5Lu_0.5B₁₂) to 7.5 μΩ  cm (Eu_0.97Gd_0.03B₆).