Low-energy electron transport in gold: mesoscopic potential calculation and its impact on electron emission yields

Abstract

In a previous work, we extended and benchmarked the MDM Monte Carlo code with available data for gold metallic media irradiated by electron beams. In this paper, we worked with the aim of improving the cross sections on which our Monte Carlo simulation is based, and which are essential for an accurate description of the transport of electrons in gold. The mesoscopic potential of solid gold has been predicted, and its sensitivity toward electron emission has been evaluated. This potential was derived from the calculation of the electrostatic and atomistic potential by density functional theory and used to calculate inelastic inverse mean free path for electron transport. After integrating these results into our Monte Carlo code, we evaluated the impact of these new cross sections on yields of electron emission from solid gold irradiated by monoenergetic electron beams. We obtained a mesoscopic potential value of − 12.77 eV for our model of bulk metal gold, 27% lower than the one commonly estimated from the Fermi energy. This result impacted on the inverse mean free path for plasmon excitations with a 10% decrease for electrons in the range of 6–30 eV. Regarding electron emission yields, there was no impact of the new mesoscopic potential on the primary electron yields, but for secondary electrons, the emission yields were increased by a factor of up to two depending on the primary beam energy and thickness of the gold foil.