Surface and interface study of cermet coatings on aluminized steel by XPS

Cermet (Ag-ZrO2) coatings have been deposited by spray pyrolysis on an aluminized steel (AS) sheet of large area, using two different coating procedures: i) first spraying silver particles, and above that layer a film of zirconia, or ii) simultaneously spraying zirconia and the silver particles using a unique spray solution with Zr and Ag precursors. XPS surface and subsurface analysis, with the help of mild Ar+ etching, has shown that the silver particles are metallic. On the surface of the silver particles exists a very thin oxide layer of silver zirconate. After Ar+ etching, the Ag-ZrO2 coating material exhibits two phases showing differential charging. Both types of coatings reveal similar XPS spectra during analysis, albeit the coating obtained from the unique spray solution presents XPS peaks of slightly smaller width. SEM observations show that smaller silver particles with a smaller particle size distribution are obtained when spraying with a unique spray solution. Copyright (C) 2010 John Wiley & Sons, Ltd.