FIELD-EMISSION SPECTROSCOPY

The first experimental evidence of the existence of electron states localised on a clean metal surface was available to us since 1967 in the form of the well known Swanson-Crouser hump in the energy distribution of electrons field-emitted from the W(100) plane, although it took some time before its interpretation as such, in 1976, was established beyond any doubt. Subsequently, angle-resolved photoemission proved to be a more competitive method for the investigation of surface states of metals and semiconductors. However, field emission remains a useful tool in surface physics research. After a brief introduction to field emission spectroscopy, we review recent work which shows the potentiality of this technique in the investigation of the surface properties of semiconductors, ferromagnetic metals, thermal superconductors, and of the electronic structure of supported clusters.