When preparing an alternating sequence of magnetic (Co or Ni) and non-magnetic (Cu)
layers by electrodeposition using the two-pulse plating technique, a dissolution of the lessnoble
magnetic Co and Ni atoms can take place during the deposition of the more noble and
non-magnetic Cu atoms. This process results in changes of the actual sublayer thicknesses
with respect to the nominal values and can also cause some chemical intermixing at the
magnetic/non-magnetic interfaces. As a consequence, superparamagnetic (SPM) regions
with “loose magnetic moments” can form as has been demonstrated for electrodeposited
Ni-Cu/Cu multilayers. We have also shown recently for electrodeposited Co-Cu/Cu
multilayers that if some fraction of the magnetic layers exhibits SPM behaviour then the
observed giant magnetoresistance (GMR) can be quantitatively decomposed into a
ferromagnetic (FM) and a SPM contribution. In this paper, the results of a similar GMR
decomposition study are presented for two electrodeposited Co-Cu/Cu multilayers. In the
multilayer with strongly non-saturated magnetoresistance curves, the dominant GMR term
was due to SPM regions, whereas in the other multilayer for which the magnetoresistance is
mostly saturated in magnetic fields around 1 to 2 kOe, the FM contribution to the GMR is
much larger. At the same time, magnetic measurements on the first multilayer sample have
also revealed the presence of a large SPM contribution to the magnetization
