Effect of substrate temperature and deposition rate on alloyzation for Co or Fe onto Cu(001) substrate

Abstract

The mixing situation of Fe or Co atoms implanting onto Cu(001) substrate is investigated with regard to substrate temperature and deposition rate by molecular dynamics. The tight-binding-second-momentum-approach many-body potential is used to model the atomic interaction. The results indicate that the morphology of the layer is under epitaxial growth as the substrate temperature is 700 or 1000 K, while it is not epitaxial at the substrate temperature of 300 or 450 K. The quality of epitaxial film is better when the substrate temperature is increased. The intermixing at the deposited layers becomes clear as the substrate temperature increases. It also indicates that there are more Co atoms penetrating into the substrate than the Fe atoms, regardless of the substrate temperature. Hence, one could say that the interface mixing of Co and Cu atoms is better than that of Fe and Cu atoms. When the deposition rate is raised from 5 to 10 atoms/ps, there is no increase in the interface mixing at both systems except for that at low substrate temperature. Furthermore, the first peak of the radial distribution function becomes lower and wider for both the Fe–Cu and Co–Cu systems as the substrate temperature is increasing from 300 to 1000 K.