X-ray photoemission study of Fe-Al2O3 granular thin films

Granular Fe-Al2O3 thin films, composed of small iron particles dispersed in an amorphous alumina matrix, have been analyzed as a function of the composition and of the depth by x-ray photoemission spectroscopy. The surface of all the samples is composed of a fully oxidized Fe3+ form within an alumina-rich partly hydrated region, and the surface quantitative composition is highly dependent on the bulk composition. After Ar+ etching, metallic iron and iron aluminates become apparent. The concentration of the first species increases with increasing depth and the iron content in the bulk of the granular films. © 1983 The American Physical Society.