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Auger Electron Emission in the Energy Spectra of Secondary Electrons from Mo and W

1956; American Institute of Physics; Volume: 102; Issue: 2 Linguagem: Inglês

10.1103/physrev.102.340

1536-6065

G. A. Harrower,

Corrosion Behavior and Inhibition

With the aim of determining to what extent the energy distribution of secondary electrons from targets of Mo and W may contain fine structure, measurements have been made using primary energies from 100 to 2000 electron volts. An electrostatic analyzer of the 127-degree type having an experimentally determined resolution of one percent was used. Observations of the pressure in the vacuum system, after heating the target above 2000\ifmmode^\circ\else\textdegree\fi{}K and cooling to room temperature, showed that an energy spectrum could be recorded before formation of the first monolayer of contamination on the target surface.Energy distribution measurements revealed: (1) Several subsidiary maxima at fixed differences in energy from the primary energy, these differences being characteristic of the target material and independent of the primary energy itself. (2) Several subsidiary maxima in the energy distribution at fixed positions along the energy scale lying between 10 and 500 electron volts, characteristic of the target material, and independent of the primary voltage. The maxima described in (1) are considered to be primary electrons reflected after suffering discrete losses of energy to the target. These discrete losses are believed to indicate the positions of the higher energy levels of the target material. The maxima described in (2) are interpreted as Auger electrons. Combining the energy level values determined from the discrete loss measurements with energy values for the deeper lying levels available from x-ray studies, it is possible to predict the energies with which Auger electrons might be expected to be emitted. Some of the predicted energies for Auger electrons agree reasonably well with with the energies observed experimentally both for Mo and for W.