Surfactant-mediated growth of Cu on Co(0001) investigated using medium-energy ion scattering

Experiments were carried out using medium energy ion scattering (MEIS) to compare the structural properties of Cu films deposited on Co(0001) both with and without surfactant and before and after annealing to 300 °C. Films of 10-ML thickness were deposited onto the clean Co surface and onto a surface pre-dosed with 1 ML of Pb surfactant. MEIS data revealed a twinned fcc structure in all the deposited films irrespective of the presence of surfactant or the use of post deposition annealing. In the case of the Pb deposited surfaces the majority of surfactant was seen to float on the surface during growth but with a small quantity becoming distributed throughout the film. In addition to allowing 1-2 extra monolayers to grow epitaxially, the MEIS data provided evidence of improved crystallinity for films grown with the surfactant. Annealing the sample to 300 °C appeared to have little or no effect on the deposited films.