Magnetoresistance and Anomalous Hall Effect with Pt Spacer Thickness in the Spin-Valve Co/Pt/[Co/Pt]2 Multilayers

In the spin-valve Co/Pt/[Co/Pt]2 multilayers with perpendicular magnetic anisotropy, it has been found that magnetoresistance, anomalous Hall resistivity, and longitudinal resistivity demonstrate oscillatory behaviors with the increase in Pt spacer thickness. Moreover, the parameter b oscillates as a function of Pt spacer thickness, which is experimentally determined by fitting the equation \(\rho _{AH} =a^{\prime }\rho _{xx0} +b\rho _{xx}^{2} \) (ρ x x0 is the residual resistivity, a ′ is the skew scattering parameter, and b consists of the side jump and the intrinsic contributions) via the temperature dependence of the resistivity. These observed oscillatory behaviors can be mainly ascribed to the polarization of Pt spacer, while the polarization in the Co/Pt multilayers depends on the Pt spacer thickness.