In situ surface analysis by low energy ion scattering

We discuss the possibilities to apply low energy ion scattering (LEIS) for in situ surface analysis of devices and functional materials. First we disc uss the limitations imposed by the technique such as pressure and spatial r esolution. Next, we present a new method to suppress backgrounds in LEIS sp ectra due to the presence of light elements by using a combined electrostat ic and flight-time analysis. Examples of in situ analysis on thermionic cat hodes are presented which shed light on the surface structure and compositi on of these cathodes, and also allow us to study the resistivity of such ca thodes to ion bombardement. Finally, a design is presented for a pressure c ell for in situ surface analysis of catalysts during catalytic reaction. (C ) 2000 Elsevier Science B.V. All rights reserved.