Photon- and electron-stimulated desorption of O+ from zirconia

We present a study of the photon- and electron-simulated desorption (PSD and ESD) of cations from yttria-stabilized cubic ZrO2(100) and undoped amorphous ZrO2 surfaces. For both types of zirconia, O+ is the primary ionic desorption product. A weak threshold for ESD of O+ from yttria-stabilized cubic zirconia (YSZ) is observed at similar to 26-27 eV with a rapid rise above similar to 30 eV. The PSD threshold from YSZ is similar to 31 +/- 1 eV. This is essentially the same as the O+ ESD and PSD thresholds (similar to 30 +/- 1 eV) from undoped amorphous ZrO2 surfaces. The PSD O+ kinetic energy distributions extend from 0 to similar to 7 eV with a peak at similar to 2 eV and are similar from both surfaces. A comparison of the ion threshold data with photoelectron spectra indicates that desorption of O+ is primarily initiated by excitation of the Zr(4p) core level. All of the evidence is consistent with a desorption mechanism, in which the O+ ions are produced and ejected from the surface via a multi-electron Auger decay process. (C) 1999 Elsevier Science B.V. All rights reserved.