Resistance and magnetoresistance studies in (Co/Nb) multilayers before and after ion-mixing

(Co/Nb) multilayers have been prepared by sequential deposition under UHV conditions. Resistivity and magnetoresistance were measured in the temperature range 3-300 K and in a magnetic field of 0-7.2 T. The specific resistivity ρ{variant} is increasing with increasing temperature. The ratio ρ{variant}(300 K)/ρ{variant}(4.2 K) decreases with an increase in the number of bi-layers. Investigations were also made on some samples subjected to ion-mixing in order to find the specific effect of the layered structure. A qualitative model has been proposed.