Effect of the Applied Current Density on the Structural and Magnetic Properties of the Electrodeposited Cobalt-Nickel Alloy Thin Films

In this study, cobalt-nickel (Co-Ni) alloys were deposited electrochemically onto aluminum substrates under applied current densities of 103.8, 138.4, 173 and 207.6 A m¯². Influence of the applied current density on the structural and magnetic properties of the Co-Ni alloys was investigated. The bath for Co-Ni alloys deposition was composed of 0.08 mol l¯¹ CoSO₄·7H₂O, 0.2 mol l¯¹ NiCl₂·6H₂O, 0.1 mol l¯¹ NiSO₄·6H₂O and 0.25 mol l¯¹ H₃BO₃. The electrochemical investigation of Co-Ni alloys was completed using cyclic voltammetry and galvanostatic studies. Inductively coupled plasma analysis has shown that the amount of the cobalt in the deposited alloy has decreased from 73.61% to 67.01% with the increase of the applied current density from 103.8 to 207.6 A m¯². According to the magnetic analysis results, the values of coercivity coefficient of the deposited Co-Ni alloys range between 115 and 150 Oe, confirming ferromagnetic behavior of the alloys. Experiment results indicate that magnetic and structural properties of the Co-Ni alloy deposits are greatly influenced by the applied current density in the electrodeposition system.