| AVS 56th International Symposium & Exhibition | |
| Surface Science | Tuesday Sessions |
| Session SS1-TuM |
| Session: | Oxide Surfaces: Reactions and Structure |
| Presenter: | R.D. Gann, University of California, Riverside |
| Authors: | R.D. Gann, University of California, Riverside J. Wen, Brookhaven National Laboratory Z. Xu, Brookhaven National Laboratory G.D. Gu, Brookhaven National Laboratory R.Q. Wu, University of California, Irvine J.A. Yarmoff, University of California, Riverside |
| Correspondent: | Click to Email |
The high-Tc cuprate BSCCO-2212 is investigated with low energy (0.5-10 keV) alkali ion scattering, which is an extremely surface-sensitive technique that can reveal compositional, structural and electronic information about a surface. Samples were cleaved at liquid nitrogen temperature in ultra-high vacuum, and time-of-flight spectroscopy was used to measure charge-resolved energy spectra of the scattered ions. Clean surfaces were shown to be terminated by BiO, and the inhomogeneous surface potential of the as-cleaved surface was revealed by the angular dependence of the neutralization. The effect on local potential due to adsorption of alkali and halogen species was ascertained by neutralization measurements and verified with density-functional theory. Deliberate damage induced by 500 eV argon sputtering revealed a gradual disordering of the surface as underlying metallic species diffuse upward, rather than layer-by-layer etching, as earlier SIMS studies have suggested. A detailed view of the surface termination opens the door for studies of other, similarly layered materials such as Bi2Se3.