Pulse plating of cobalt-iron-copper alloys

Pulse plating of cobalt-iron-copper (CoFeCu) alloys was studied. A simple t heoretical 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 betwe en 5 to 20 wt%. These compositions are of interest as soft magnetic materia ls with high saturation magnetization. The deposits were produced from a bo ric acid and sodium acetate electrolyte with low concentrations of copper a nd iron. All experiments were carried out under well-controlled mass transp ort conditions and current distribution using a recessed rotating cylinder electrode (rRCE) or an inverted rotating disc electrode (IrRDE). With the l atter design alloys can be plated on flat substrates with or without applic ation of a magnetic field to induce uniaxial magnetic anisotropy. Results s how that by changing pulse parameters one can increase and decrease in oppo site ways the copper and the iron content in the deposits. To test the infl uence of pulse parameters on the coercive field strength, a microstructure dependent property, theoretical predictions were used to produce films of i dentical composition with different pulse parameters. Within the range of p ulse 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.