Comparison of Processes Occurring during Silver Adsorption on Copper and Nickel at Elevated Temperatures

A flux of silver atoms reevaporated from the copper and nickel targets during deposition of silver was measured as a function of the target temperature during spontaneous cooling from 1150 K and during heating the target with deposited several silver monolayers from room temperature to 1150 K. Differences in the measured dependences for both targets give the evidence of competition between reevaporation of silver atoms from the copper surface and their dissolution in the copper bulk and are in accordance with the lack of silver dissolution in nickel. Thus, the role of silver dissolution in the copper surface layer during silver adsorption at elevated temperatures is experimentally evidenced. Activation energy for silver dissolution in the copper substrate was estimated to be equal to 1.7-2.4 eV/atom