ESCA Investigation of the surface of mixed precipitates.

Quantitative ESCA has been used for studying the surface of mixed precipitates. When the precipitation is complete and homogeneous, as with titanium and zirconium hydroxides, almost complete correlation is found between the atomic ratio of the elements in the precipitate and that estimated by the Hirokawa-Ebel method, but not for incomplete mixed precipitation, as with copper and silver hydroxides. When precipitated copper and silver are reduced to the metals with iron or zinc, the surface is enriched in copper.