Besides, a decrease in the Gibbs free surface energy γ would relate to a smaller rcrit (equation ( )). However, gold surfaces are highly stabilized by chloride. Although the relative concentration of Cl -decreases with the initial HAuCl4 concentration at the electron flux density range of interest, the absolute concentration still increases. Consequently, the gold surface is considered to remain saturated with Cl -in all conducted experiments, and, thus, changes in γ are expected to be negligible.