AUGER-ELECTRON SPECTROSCOPY ELEMENT PROFILES AND INTERFACE WITH SUBSTRATES OF ELECTROLESS DEPOSITED TERNARY ALLOYS

Electroless NiMeP alloys (Me = Cu, Sn, Sb) with high phosphorus conten t (similar to 11 weight percent) and a low weight percent of the third component (Me) have been plated in acidic baths onto aluminum, iron, and nickel. Scanning Auger electron spectroscopy is applied to study t he element profiles and interface with the substrates. Generally the t hird component follows the profiles of Ni and P, which proves the allo y formation. A surface enrichment in the third element (Me) is observe d in all cases. It is very strong when tin is the third component and very weak in the case of antimony, which is more or less uniformly dis tributed through the thickness. Decrease of surface concentration of p hosphorus is noticed when NiSbP is plated. In Cu profiles three differ ent zones exist: a surface enrichment zone, a groove (a zone of reduce d concentration), and a plateau (a zone of almost constant concentrati on). There is no enrichment in the third element at the interface with the substrate for all three alloys and three substrates. At the inter face with aluminum prepared for electroless plating with double zincat e pretreatment complete dissolution of the zincate layer has been esta blished.