Electron-stimulated desorption of positive and negative oxygen ions from YBa2Cu3O7 surfaces

Abstract

Electron-stimulated desorption of positive and negative oxygen ions from YBa2Cu3O7 surfaces has been studied as a function of electron kinetic energy in the 70–600 eV range. It has been found that the threshold electron kinetic energy needed to induce positive oxygen ion desorption occurs at 260±5 eV, whereas that associated with negative oxygen ion desorption was found to be 100±5 eV. These electron kinetic energies correspond to Cu, Y, and Ba core-level binding energies. These results suggest that negative and positive oxygen ion desorption may be initiated via a primary core level ionization.