Production of atomic-oxygen negative-ion beam by positive ion-induced sputtering of semiconductive BaTiO3 ceramic

When a semiconductive BaTiO3 ceramic surface is bombarded by a keV positive-ion beam, atomic-oxygen negative ions are emitted from the surface in number several tens of times greater than the numbers of other negative ions and neutrals. The dependence of the number of oxygen negative ions on the angle of incidence, the energy and the mass of the bombarding positive ions was investigated, and the ion yield was estimated to be several times greater than 0.1 for the typical conditions. The significance of this finding on techniques for producting negative ions is discussed. (author)