Current-perpendicular-to-plane magnetoresistance (CPP-MR) measurements let us quantify conduction electron scattering and spin flipping at a sputtered ferromagnetic/ferromagnetic $\left(\text{F}1/\text{F}2=\text{Co}/\text{Ni}\right)$ interface, with important consequences for CPP-MR and spin-torque experiments with perpendicular anisotropy. We use ferromagnetically coupled ${\left[\text{Ni}/\text{Co}\right]}_n\text{Ni}$ multilayers, and Py-based, symmetric double exchange-biased spin valves containing inserts of ferromagnetically coupled ${\left[\text{Co}/\text{Ni}\right]}_n\text{Co}$ or ${\left[\text{Ni}/\text{Co}\right]}_n\text{Ni}$ multilayers, to derive Co/Ni interface specific resistances $A{R}_{\text{Co}/\text{Ni}}^{\uparrow }={0.03}_{-0.03}^{+0.02}\text{f}\Omega {\text{m}}^2$ and $A{R}_{\text{Co}/\text{Ni}}^{\downarrow }=1.00\pm 0.07\text{f}\Omega {\text{m}}^2$, and interface spin-flipping parameter ${\delta }_{\text{Co}/\text{Ni}}=0.35\pm 0.05$. The specific resistances are consistent with our no-free-parameter calculations for an interface thickness between 2 and 4 monolayers that is compatible with expectations.

• Received 13 October 2010

DOI:https://doi.org/10.1103/PhysRevB.82.220401