화학공학소재연구정보센터
Journal of Applied Electrochemistry, Vol.31, No.2, 137-144, 2001
Pulse plating of cobalt-iron-copper alloys
Pulse plating of cobalt-iron-copper (CoFeCu) alloys was studied. A simple theoretical model with an analytical solution developed for binary alloys is applied to predict the copper content of the pulse plated ternary alloys. Studied compositions are in the range of Co90-xFe10Cux with x varying between 5 to 20 wt%. These compositions are of interest as soft magnetic materials with high saturation magnetization. The deposits were produced from a boric acid and sodium acetate electrolyte with low concentrations of copper and iron. All experiments were carried out under well-controlled mass transport conditions and current distribution using a recessed rotating cylinder electrode (rRCE) or an inverted rotating disc electrode (IrRDE). With the latter design alloys can be plated on flat substrates with or without application of a magnetic field to induce uniaxial magnetic anisotropy. Results show that by changing pulse parameters one can increase and decrease in opposite ways the copper and the iron content in the deposits. To test the influence of pulse parameters on the coercive field strength, a microstructure dependent property, theoretical predictions were used to produce films of identical composition with different pulse parameters. Within the range of pulse parameters studied the coercive field strength of this alloy does not vary. Transmission electron microscopy confirms that the deposits have the same nano-size grain structure.