Pitting corrosion of electroplated permalloy films

The corrosion resistance of electroplated permalloy films (Ni-20% Fe) has been shown to be inferior to that of material of the same nominal composition, but fabricated by other processes. Evidence is presented to support the notion that this corrosion susceptibility is due to sulfur that is incorporated into the plated alloy in the form of saccharin, a plating bath additive. An Fe-rich transition region deposited at the onset of plating may create an area of enhanced susceptibility for devices that expose a cross-section of the structure to the environment. © 1993.