Permalloy plating

Nickel, used extensively to make coins and nickel steel for armor plates and burglar-proof vaults, and is also a component in Nichrome(R), Permalloy(R), and constantan. 

Electroless Electrolytic Plating. In electroless or autocatalytic plating, no external voltage/current source is required (21). The voltage/current is suppHed by the chemical reduction of an agent at the deposit surface. The reduction reaction must be catalyzed, and often boron or phosphoms is used as the catalyst. Materials that are commonly deposited by electroless plating (qv) are Ni, Cu, Au, Pd, Pt, Ag, Co, and Ni—Fe (permalloy). In order to initiate the electroless deposition process, a catalyst must be present on the surface. A common catalyst for electroless nickel is tin. Often an accelerator is needed to remove the protective coat on the catalysis and start the reaction. 

A well-known example of anomalous alloy deposition is the plating of Permalloy . Considering that the values of TI for... 

Initial experiments showed that the PMDA/ODA material can be successfully cured by a ot plate bake at 280° C for 3 hours. Electrical.Loss tangent data showed that imidization was complete under these conditions. As noted before,the passivation process for bubble devices had to be optimized by using a lower temperature ( to preserve the magnetic properties of the permalloy structures).without losing the electrical insulation characteristics of the final polyimide. IR technique was used as the method of detecting complete cure. A Perkin Elmer 283 spectrometer was used for the IR analyses routinely,and in a few cases the results were checked with a Digilab FTIR instrument.Routine resolutions were 2cm with the Perkin Elmer instrument. Jh s g-dies of imide formation by IR is a well known technique ... 

The beneficial additive effect on stress evolution during electrodeposition is shown in Fig. 16. In (A), from in situ measurements, one can see that for Permalloy films of 100 nm thickness, the significant stress reduction in deposit is achieved if saccharin (stress reduction 50%) or 1-Methionine (stress reduction 85%) is used as additives in plating solution. The effect of saccharine concentration on stress in electrode-posited CoNiFe films is shown in Fig. 16(B). These data suggest that stress reduction is decreasing towards asymptotic value for increasing saccharin content in the solution. 

The method of deposition has been reported to have a large influence on the corrosion properties of permalloy [149-151]. In particular, plated permalloy films have been found to be more susceptible to corrosion than either bulk material or vacuum-deposited films of nominally the same composition. For instance, sputter-deposited permalloy was found to passivate in pH 2 solutions, but plated films did not [150]. Another study in neutral chloride solutions showed that plated permalloy had a lower pitting potential than bulk permalloy [151]. These reports suggested that plated films either have regions locally enriched in Fe or have a crystallographic orientation that is more susceptible to attack. However, little supporting evidence was provided. 

An explanation for the enhanced corrosion susceptibility of plated permalloy films was offered in a study that examined the walls of pits in thin-film samples using Auger electron spectroscopy [149]. The pit walls showed a large enhancement of... 

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