Journal of The Electrochemical Society, 158 (11) D671-D680 (2011) D671 0013-4651/2011/158(11)/D671/10/$28.00 © The Electrochemical Society Magnetoresistance and Surface Roughness Study of the Initial

The giant magnetoresistance (GMR) effect has been widely investigated on electrodeposited ferromagnetic/non-magnetic (FM/NM) multilayers generally containing a large number of bilayers. In most applications of the GMR effect, layered structures consisting of a relatively small number of consecutive FM and NM layers are used. It is of great interest, therefore, to investigate the initial stages of GMRmultilayer film growth by electrodeposition. In the presentwork,we have extended our previous studies onEDGMRmultilayers to layered structures with a total thickness ranging from a few nanometers up to 70 nm. The evolution of the surface roughness and electrical transport properties of such ultrathin ED Co/Cu layered structures was investigated. Various layer combinations were produced including both Co and Cu either as starting or top layers in order (i) to see differences in the nucleation of the first layer and (ii) to trace out the effect of the so-called exchange reaction. Special attention was paid to measure the field-dependence of the magnetoresistance, MR(H) in order to derive information for the appearance of superparamagnetic regions in the magnetic layers. This proved to be helpful for monitoring the evolution of the layer microstructure at each step of the deposition sequence