Stress relaxation during two-dimensional pseudomorphic epitaxial growth of metals

The analysis of RHEED diffraction peaks during two-dimensional (2D) pseudomorphic epitaxial growth leads to the well known RHEED oscillations but also to diffraction peak width and in-plane lattice spacing oscillations. These behaviors are evidenced in several metallic A/B systems in this paper. As in-plane lattice spacing oscillations are assumed to be due to elastic relaxation at the edge of the 2D Islands, we try to correlate the amplitude of the detected effect with the misfit. The width oscillations are assumed to be due to the scattering coming from islands. We actually show that the full width at half maximum (FWHM) at half coverage allows us to get a correct estimation of the nucleation density. We thus show experimentally that the in-plane lattice spacing oscillations amplitude depends on the nucleation density determined using FWHM measurements. Finally, a theoretical justification allows us to show that this amplitude also depends on the Young modulus ratio of both B and A layers.