Variable temperature scanning tunneling microscopy experiments reveal that in Ir(111) homoepitaxy islands nucleate and grow both in the regular fcc stacking and in the faulted hcp stacking. Analysis of this effect in dependence on deposition temperature leads to an atomistic model of stacking-fault formation: The large, metastable stacking-fault islands grow by sufficiently fast addition of ada...

It has been proposed that a long-period stacking ordered (LPSO) structure is responsible for the excellent mechanical properties of lightweight alloys of Mg-Y-RE (RE: rare earth elements) system. In this study, the phenomenological simulation model for describing the formation process of the LPSO structure in Mg­Y­Zn system is constructed by means of the phase-field method. The results obtained...

The energies of the intrinsic stacking fault in 20 tetrahedrally coordinated crystals, determined by electron microscopy from the widths of extended dislocations, range from a few mJ/m to 300 mJ/m. The reduced stacking fault energy (RSFE: stacking fault energy per bond perpendicular to the fault plane) has been found to have correlations with the effective charge, the charge redistribution inde...

When load is applied to fcc nanograins, leading partial dislocations nucleate at grain boundary steps and propagate into the grain, leaving stacking faults behind. The extent to which these faults expand before a trailing partial is emitted generally does not equal the equilibrium separation distance of the corresponding full dislocation. Here we use a density functional theory – phase field di...

Twenty-one ^110& symmetric tilt grain boundaries ~GB’s! are investigated with atomistic simulations, using an embedded-atom method ~EAM! potential for a low stacking-fault energy fcc metal. Lattice statics simulations with a large number of initial configurations are used to identify both the equilibrium and metastable structures at 0 K. The level of difficulty in finding the equilibrium struct...

The governing equation of screw dislocations in heterostructures is constructed using image method. The interface type (−1 ≤ γ ≤ 1) and distance between dislocation and interface h are considered in the new equation. The Peierls–Nabarro equations for screw dislocations in bulk and semi-infinite materials can be recovered when γ = 0 and γ = −1. The soft (γ < 0) and hard (γ > 0) interfaces can en...

Significant hardening effect due to Fe concentrations in Ni-based alloys with face-centered-cubic structure has been studied by using a combined experimental and atomistic-based computational approach via nanoindentation tests. The obtained load–displacement data for the [0 0 1] crystal orientation reached qualitative good agreement molecular dynamics simulations results, leading strong evidenc...