  Current-perpendicular-to-plane magnetoresistance (CPP-MR) measurements let us
quantify conduction electron scattering and spin-flipping at a sputtered
ferromagnetic/ferromagnetic (F1/F2 = Co/Ni) interface, with important
consequences for CPP-MR and spin-torque experiments with perpendicular
anisotropy. We use ferromagnetically coupled ([Ni/Co]xn)Ni multilayers, and
Py-based, symmetric double exchange-biased spin-valves (DEBSVs) containing
inserts of ferromagnetically coupled ([Co/Ni]xn)Co or ([Ni/Co]xn)Ni
multilayers, to derive Co/Ni interface specific resistances AR(Co/Ni)(Up) =
0.03 (+0.02)(-0.03) f-ohm-m^2 and AR(Co/Ni)(down) = 1.00 +/- 0.07 f-ohm-m^2,
and interface spin-flipping parameter delta(Co/Ni) = 0.35 +/- 0.05. The
specific resistances are consistent with our no-free-parameter calculations for
an interface thickness between 2 and 4 monolayers (ML) that is compatible with
expectations.
