Characterising palladium-silver and palladium-nickel alloy membranes usingSEM, XRD and PIXE

Palladium alloy membranes were prepared by successive electroless plating s teps on an alumina-zirconia support membrane. Palladium, silver and nickel were deposited in layers and then the metal films were hear treated for 5 h in a hydrogen atmosphere at 650 degrees C. The topography of the metal coa tings and cross-sections of the films (before and after heating) were chara cterised using scanning electron microscopy (SEM). XRD was used to determin e the crystal phase of the alloy coatings. Both SEM and XRD provide only su rface information and therfore micro-PIXE was used to extract depth informa tion of the alloy coating. Concentration profiles across the thickness of t he films were constructed to determine penetration of the coating into the support membrane pores during electroless plating and to investigate diffus ion of coated layers during the heating step. (C) 1999 Elsevier Science B.V . All rights reserved.