Anomalous Hall resistivity of cobalt films:: Evidence for the intrinsic spin-orbit effect -: art. no. 060412

We report the anomalous and ordinary Hall resistivities, rho(AH)(T) and rho(OH)(T), measured on 10-200 nm thin polycrystalline Co films between 50 and 350 K. Analyzing rho(AH) in terms of the zero-field resistivity rho(T) reveals the Hall conductivity sigma(xy) as the dominant contribution , while impurity induced skew scattering remains much smaller. Since, in contrast to rho(T), the Hall conductivity turns out to be independent of structural disorder and phonons, sigma(xy)=240 Omega cm(-1) should entirely be determined by the spin-orbit split band structure, as it was proposed in early theories and, more recently, realized for Fe by calculations of the k-space Berry phase of occupied Bloch states [Yao , Phys. Rev. Lett. 92, 037204 (2004)]. Also, our results rule out a recent, modified skew-scattering model for rho(AH).