Strain dependence of surface diffusion: Ag on Ag(111) and Pt(111)

Strain dependence of surface diffusion: Ag on Ag„111... and Pt„111..

Using density-functional theory with the local-density approximation and the generalized gradient approximation we compute the energy barriers for surface diffusion for Ag on Pt~111!, Ag on one monolayer of Ag on Pt~111!, and Ag on Ag~111!. The diffusion barrier for Ag on Ag~111! is found to increase linearly with increasing lattice constant. We also discuss the reconstruction that has been fou...

Effect of strain on surface diffusion and nucleation.

Effect of strain on surface diffusion in semiconductor heteroepitaxy

We present a first-principles analysis of the strain renormalization of the cation diffusivity on the GaAs(001) surface. For the example of In/GaAs(001)-c(4 × 4) it is shown that the binding of In is increased when the substrate lattice is expanded. The diffusion barrier ∆E(ε) has a non-monotonic strain dependence with a maximum at compressive strain values (ε < 0), while being a decreasing fun...

Diffusion of large two-dimensional Ag clusters on Ag(100).

Scanning tunneling microscopy shows that large two-dimensional Ag clusters on Ag(100) can diffuse. The value of the diffusion coefficient at room temperature is of order 10-17 cm2s-1 and varies little, if at all, with cluster size in the range studied, 100 to 720 atoms per cluster. This weak variation rules out periphery diffusion as the main mechanism of cluster diffusion, suggesting instead t...

Temperature and strain-rate dependence of surface dislocation nucleation.

Dislocation nucleation is essential to the plastic deformation of small-volume crystalline solids. The free surface may act as an effective source of dislocations to initiate and sustain plastic flow, in conjunction with bulk sources. Here, we develop an atomistic modeling framework to address the probabilistic nature of surface dislocation nucleation. We show the activation volume associated w...