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We present a coherent ab initio, i.e. parameter free, description of the anomalous Hall effect (AHE) that is applicable to pure as well as disordered alloy systems by treating all sources of the AHE on equal footing. We employ an implementation of the Kubo-Streda equation using the fully relativistic Korringa-Kohn-Rostoker (KKR) Green's function method in conjunction with the Coherent Potential Approximation (CPA) alloy theory. Applications to the pure elemental ferromagnets bcc-Fe, hcp-Co and fcc-Ni lead to results in full accordance to previous ab initio studies determining the intrinsic contribution only. However, the power of the approach presented is the ability to explicitly treat also extrinsic contributions to the AHE which is demonstrated by an application to the fcc alloy systems Fe_xPd_1-x, Co_xPd_1-x and Ni_xPd_1-x. We obtain a very satisfying qualitative agreement with experiment over the whole concentration range including the sign reversal of the AH-conductivity. A detailed discussion of skew and side-jump scattering processes exemplifies the capability of the proposed method. |
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