Giant magnetoresistance in Co-Ag granular films prepared by electrodeposition

Preparation of granular magnetic Co-Ag films produced by pulsed electrodeposition from a chloride bath containing both cobalt ions and a low concentration of silver has been investigated. Deposition of cobalt on Ag is performed by a double pulse method. Combining in situ electrochemical and microgravimetric measurements, the kinetics of silver and cobalt reduction are presented. The thickness and deposition rates are monitored using an electrochemical quartz crystal microbalance (EQCM) during the growth of each material. Magnetic measurements have shown a superparamagnetic behavior in agreement with the existence of very small cobalt particles. Giant magnetoresistance (GMR) of similar to2% at room temperature is observed for the Co5Ag95 sample. (C) 2002 Elsevier Science B.V. All rights reserved.