| Resumo: | We study experimentally the Hall resistivity of Y2Fe17−xCox single crystals with x≤4 for wide temperature and applied magnetic field ranges and for various magnetic field orientations with respect to the easy-magnetization axis. For small x, the anomalous Hall effect (AHE) is very anisotropic in these naturally layered compounds. For x≤2, the AHE resistivity, measured with an applied magnetic field H⊥c axis, is nearly 1 order of magnitude larger than the AHE resistivity for H along the hard-magnetization direction (H∥c axis). Furthermore, the former is very large and varies linearly with the longitudinal resistivity ρ, whereas the latter increases as ρ2. The behavior of the AHE for H∥c axis comes quite likely from the intrinsic effect related to the hopping between different Fed orbitals. Such hopping is allowed for high-symmetry points at the crystallographic dumbbell sites in this configuration. On the other hand, interorbital hopping is not allowed for H⊥c axis. However, a huge amplitude of the AHE scattering for this configuration, which follows from skew scattering, is puzzling. Both the AHE anisotropy and the large skew scattering vanish for sufficiently high Co content. We attribute this to variations in the electronic structure of the Y2Fe17−xCox system when Co atoms start to occupy the dumbbell crystallographic sites.
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