Composition dependence of the spin-anomalous Hall effect in a ferromagnetic Fe-Co alloy

We investigated the spin-anomalous Hall effect (SAHE) in ferromagnetic Fe-Co binary alloys with different compositions. The ferromagnetic resonance (FMR) measurement in Fe1-xCox/Ti/Py trilayer structures was performed to detect the SAHE in Fe1-xCox. The modulation of FMR linewidth in the Py layer due to the SAHE was observed. The effective spin-anomalous Hall angle changed from a positive value (+0.027 atx = 0.15) to a negative value (-0.012 atx = 0.65) with increasing Co composition. This study provides a deeper understanding of the SAHE.