Electrodeposition of Soft Magnetic Fe-W-P Alloy Coatings from an Acidic Electrolyte

Fe-W-P coatings were deposited from a newly developed electrolytic bath. The effect of plating parameters, such as electrolyte current density and pH has been studied. It was found that the pH has a very strong effect on the phosphorous content of the coatings. Metallic-like, non-powdery alloys of Fe-W-P deposits with no cracks (lowly stressed) can be obtained at a lower pH (<3), exhibiting high phosphorus (up to 13 at.%) and low tungsten (6 at.%) contents. At a higher pH (>3), the composition changes to low phosphorus and high tungsten content, showing a matte, greyish, and rough surface. The applied current density also influences the morphology and the amount of phosphorous content. The deposits showed an amorphous structure for all samples with soft ferromagnetic properties.