Giant magnetoresistance of electrodeposited CoNiCu/Cu multilayers

Giant magnetoresistance (GMR) has been studied in electrodeposited CoNiCu/Cu multilayers. The value of the change of resistance with field, ΔR, is almost constant when the temperature is lowered to 15 K, whereas the GMR = ΔR R is, of course, increased. The magnetic field dependence is unchanged with temperature, demonstrating that the GMR is not thermally activated. Lorentz electron microscopy was used to investigate the nature of the magnetic domains. The layers are antiferromagnetically coupled, and the domains extend without interruption for ≈ 200 nm along the layers.