Structure and stress in Cu/Au and Fe/Au systems: A molecular dynamics study

• The kinematical theory of scattering is performed to identify the structure.
• The correlation between the stress and the deformation is observed.
• The relaxation of the stress depends on the orientation of layers.
• The lattice of Fe changes its orientation relative to the Au layer in the Fe/Au system.
• The Cu layer continues the lattice of Au in the Cu/Au system.

Growth of Fe and Cu thin films on Au substrate and stress evolution were modeled using molecular dynamics simulation. The interactions in the system are described by embedded atom method. The kinematical theory of scattering is performed to identify the structure obtained from simulations. The gold layers undergo reconstruction before deposition. The deposited copper atoms do not disturb the atoms in the reconstructed gold layer, but the deposited iron atoms cause the disappearance of the reconstructed gold surfaces. In both systems Cu/Au and Fe/Au, in the early stage of growth one observes compressive stress. Next, Cu/Au systems have the compressive stress, while in the case of Fe/Au the tensile stress is observed. In the Fe/Au system, the body-centered cubic lattice of Fe changes its orientation relative to the Au layer. In the Fe/Au system we observed a larger diffusion of Au atoms than in Cu/Au systems.