Field Emission Spectroscopy of Metals

Abstract

A theory of field emission which takes into account the energy-band-structure of the metal emitter was initially proposed by Itskovich (1966, 1967). The next significant step was made by Politzer and Cutler (1972). Their calculation of the spin-polarized field emission current from ferromagnetic nickel (100) constitutes the first serious attempt to include in a quantitative calculation of this kind the energy band structure of the metal and the nature of the corresponding electronic wave functions (Bloch waves). A critical review of theoretical work relating to field emission up to the year 1972 can be found in the article of Gadzuk and Plummer (1973). Further progress was made when it was realized (Nicolaou and Modinos, 1975; Modinos and Nicolaou, 1976) that a method can be established; using the mathematical apparatus developed by LEED theorists, which allows one to calculate the energy distribution of the field-emitted electrons (the current is simply the integral of this quantity) accurately and efficiently, at least for some models of the metal-vacuum interface. The theory to be presented here is based on the above-mentioned papers and on subsequent work by the author (Modinos, 1976). The following review articles are also directly relevant to the subject matter of this chapter: Plummer (1975); Soven, Plummer, and Kar (1976); Feuchtwang and Cutler (1976); Modinos (1978a).