Introduction of ESD

• Electron-Stimulated Desorption (ESD)

  The interaction of electrons with solid surfaces can cause the removal of atomic, molecular, or ionic species from the surface. Several mechanisms are involved in these processes, which go by the general name of electron-stimulated desorption (ESD).

• Electron stimulated desorption ion angular distribution (ESDIAD)

  Measurements use low energy electrons to interact with absorbed atoms or molecules on the surface of a crystal to produce positive ions. The direction in which the ions are emitted is used to determine bond directionality.

• There are two main aspects of ESD:

  1. Several physical mechanisms involved to explain ESD phenomena from different types of surfaces and the chemical consequences of ESD effects on adsorbates.

  2. Electron Stimulated desorption ion angular distribution (ESDIAD), an powerful investigative tool for the study of the bonding and dynamical behavior of chemisorbed species.

• A wide range of surface systems studied with ESD techniques:

  1. Substrates of interest:

     • simple metals

     • transition metals

     • highly ionic oxides

     • alkali-halide solids

     • semiconductor

  2. Adsorbates of interest:

     • physisorbed noble gases

     • small chemisorbed molecules

     • large organic species

  3. Information derived from ESD:

     • bonding geometry of surface species from adsorbates on single-crystal surfaces

     • inter-molecular forces

     • bonding length and orientations of defect surface structure

     • thermal dynamics of adsorbed species

     • production and observation of synthetically catalytic intermediate species at high coverages