Periodic array of misfit dislocation loops and stress relaxation in core-shell nanowires

Abstract In this paper, we consider the mechanism of misfit stress relaxation in lattice-mismatched core-shell nanowires (NWs) through the formation of a periodic array of misfit prismatic dislocation loops (PDLs). In doing so, we calculate and analyze the stress fields and strain energy of a PDL and the energy of pair elastic interaction between PDLs in an elastically isotropic cylinder with free surface. Based on these results, the critical parameters (misfit strain, ratio of core to shell radii) for the formation of a single misfit PDL and the equilibrium spacing of misfit PDLs in the periodic array of such PDLs in a core-shell NW are found. It is shown that this equilibrium spacing well corresponds to the experimental data available in the literature.