Auger electron spectroscopy studies of clean polycrystalline gold and of the adsorption of mercury on gold

Abstract

Auger spectra of clean polycrystalline gold have been determined in a cylindrical velocity analyzer at a resolution of 0.6%. The assignment of the Auger transitions is discussed. The energy distribution curve, N(E) is obtained from the experimental d(E×N(E))/dE curve and the secondary electron background substracted in the region of the N₆VV, N₇VV doublet. Deconvolution of this region was performed on a Dupont curve resolver into four separate peaks and the two larger peaks assigned to the Auger transitions N₇VV and N₆VV. The width of each peak is ∼ 3.2 eV which compares with a value predicted from the known band structure of gold of greater than 10 eV; apparently only a part of the valence band is available for Auger emission.

The adsorption of mercury on the clean gold surface is examined at 300 K and the initial sticking probability is shown to be close to unity, falling rapidly when the coverage exceeds 4.6 × 10¹⁴ atoms cm^–2. Heating the gold to ∼ 450 K in vacuum removed all the Auger features associated with Hg.