ON THE MECHANISM OF BOMBARDMENT-INDUCED OXYGEN REDISTRIBUTION AT ZRO2SURFACES

Yttria-stabilized (100) ZrO2 crystal surface was bombarded with 10-keV He+ ions. The surface compositional changes and oxygen redistribution after the bombardment were studied using XPS. O/Zr and O/Y concentrat ion ratios were measured as a function of the photoelectron's emission angle. Oxygen enrichment at the surface and oxygen depletion in the s ubsurface region were established. The Zr3+ and Zr4+ valence states co ntent was estimated after the bombardment,as well as their distributio n as a function of the photoelectron emission angle. Using the influen ce of the carbon coverage on the signal intensify as a reference, the depth profile was estimated from all bulk elements - Zr, Y, O. The O p eak at the surface was probably near-threshold sputtering in combinati on with chemically-driven O-trapping by the lower oxidized states of Z r in the surface region. Copyright (C) 1996 Published by Elsevier Scie nce Ltd