DSC, X-ray and magnetic studies on electroless Ni-P films grown in alkaline ethanolamine baths

Abstract

Results of XRD and DSC studies on electroless Ni-P deposits obtained from two types of alkaline baths containing ethanolamines are discussed. One type (called CT-EN) employed citrate as a complexant, while the other (GEEN)used glycine as a complexant. GE-EN baths gave an amorphous deposit even at a low phosphorus content (4.8 wt.%), while deposits from CT-EN baths exhibited an amorphous nature only above 9% P. Densities of GE-EN deposits were lower than those of CT-EN deposits of similar phosphorus content. Thermograms of deposits from both baths gave a lower temperature exothermic peak. Deposits from GE-EN baths showed a splitting of the low-temperature peak. Through measurement of the saturation magnetic moment of deposits heated at temperatures corresponding to the low-temperature peak, it is shown that the exothermic processes responsible for this peak are crystallization of nickel and reorganization of the amorphous matrix. The possible reasons for the splitting are discussed. The high-temperature peak is shown to be due to formation of Ni + Ni,P.