Optimisation of electrochemical process parameters for giant magnetoresistance of electrodeposited Ni–Co(Cu)/Cu multilayers

Abstract

A methodological approach to optimise the electrochemical process parameters for giant magnetoresistance (GMR) in electrodeposited Ni–Co(Cu)/Cu multilayers has been developed. The multilayers were deposited on gold coated quartz discs in a flow channel cell by a potentiostatic dual pulse plating method from a citrate electrolyte. It has been found that GMR of these multilayers is strongly dependent on the relative amount of nickel and cobalt present in the ferromagnetic layer. GMR is also strongly dependent on the thickness of both ferromagnetic and non-magnetic layers. GMR has been found to increase linearly with increasing number of interfaces. Ni–Co(Cu)/Cu multilayers plated from citrate electrolytes of lower pH values do not exhibit GMR. Hydrodynamic condition of the electrolyte has very little effect on GMR, unlike some other reported systems.