Dissociation and desorption of ferrocene on graphite by low energy electron impact

Ferrocene is an iron-containing organometallic molecule with the potential to be used for fabrication of metallic structures on the nanometre scale. We have used high resolution electron energy loss spectroscopy and scanning tunnelling microscopy to study the influence of low energy electron impact on ferrocene physisorbed on graphite. At electron energies below 10 eV we find that the ferrocene molecules are readily desorbed, leaving a clean graphite surface behind. For energies of 20–100 eV we find evidence of partial fragmentation of the ferrocene. At higher energies, exceeding 200 eV, there is complete disintegration of the molecules, leaving iron-containing nanoclusters in a stable film on the surface. Comparisons are drawn with photon-, thermal- and very high electron-energy induced dissociation and desorption.