The electrodeposition behaviors and magnetic properties of Ni-Co films

Ni-Co films with different compositions and microstructures were produced on ITO glasses by electrodeposition from sulphate bath at 25 degrees C. Cyclic voltammograms give a result that the increase in the Co2+ concentration displaces Ni-Co alloy oxidation peaks to negative potential with high Co current distributions. It is observed that the content of cobalt in the films increases from 22.42% to 56.09% as the molar ratio of CoSO4/NiSO4 varying from 0.015/0.085 to 0.045/0.055 in electrolyte. XRD patterns reveal that the structure of the films strongly depends on the Co content in the deposited films. The saturation magnetization (M-s) moves up from 144.84 kAm(-1) to 342.35 kAm(-1) and coercivity (H-c) falls from 15.27 kAm(-1) to 7.27 kAm(-1) with the heat treatment temperature increasing from 25 degrees C to 450 degrees C. The saturation magnetization (M-s) and coercivity (H-c) move up from 340.97 kAm(-1) and 7.98 kAm(-1) to 971.58 kAm(-1) and 18.62 kAm(-1) with the Co content increasing from 22.42% to 56.09% after annealing at 450. (c) 2011 Elsevier B.V. All rights reserved.