The anomalous Hall effect (AHE) serves as a pivotal transport phenomenon for deciphering the interplay between magnetic spin textures and topological bands in magnetic materials, with its origin attributed to intrinsic (momentum-space Berry curvature linked to Weyl or Dirac point) and extrinsic (spin-dependent scattering, i. e. , skew scattering and side-jump) mechanisms. The complex magnetic structure and strong spin-orbit coupling effect of rare-earth magnetic materials make them an important platform for studying AHE. Here, we report a disordered Ho₁. ₂₅Au₀. ₇₅Si₁. ₅₅ single crystal and investigate its magnetic and transport properties. In this single crystal, Ho-Au mixed occupancy on the 2c site and vacancies on the Si 2b sublattice give rise to pronounced chemical disorder. Ho₁. ₂₅Au₀. ₇₅Si₁. ₅₅ belongs to the rare-earth ferromagnetic material with a magnetic ordering temperature of 8 K (T₂) and easy magnetization along the c axis. The magnetoresistance (MR) of Ho₁. ₂₅Au₀. ₇₅Si₁. ₅₅ exhibits different behaviors at high and low temperatures in the H and I configurations. At 3 K (T4pt{0ex}4pt{0ex}T₂), the MR remains negative as a result of the suppression of the scattering from spin fluctuations. With regard to the AHE, considering the scaling behavior between the anomalous Hall resistivity ₗₙ^A and the longitudinal resistivity ₙₙ, the origin of the AHE in Ho₁. ₂₅Au₀. ₇₅Si₁. ₅₅ can be described by the skew scattering mechanism. The dominance of skew scattering is likely driven by the structural disorder present in Ho₁. ₂₅Au₀. ₇₅Si₁. ₅₅: the Ho-Au mixed occupancy and Si vacancies create a random potential landscape and break local chemical periodicity, which are expected to enhance asymmetric carrier scattering. The anomalous Hall angle ₀₇ and anomalous Hall factor S₇ of Ho₁. ₂₅Au₀. ₇₅Si₁. ₅₅ are 0. 49% and 0. 03 V^-1, respectively, at 3 K, and both decrease as the temperature rises. The small ₀₇ and S₇ are attributed to the finite s-f exchange coupling in this 4f localized-moment ferromagnet and to the enhanced scattering environment associated with Ho-Au mixed occupancy and Si vacancies. This work establishes disordered Ho₁. ₂₅Au₀. ₇₅Si₁. ₅₅ as a platform for studying the role of structural disorder in skew-scatter-dominated AHE in rare-earth localized-moment ferromagnets.
Yue et al. (Tue,) studied this question.