A thin film of heavily B-doped diamond has been grown epitaxially by microwave plasma chemical vapor deposition on an undoped diamond layer, on top of a Ir/YSZ/Si(001) substrate stack, to study the boron segregation and boron environment at the dislocations present in the film. The density and nature of the dislocations were investigated by conventional and weak-beam dark-field transmission ele...

In this Letter, we propose a model that demonstrates the effect of a free surface on the lattice resistance experienced by a moving dislocation in nanodimensional systems. This effect manifests in an enhanced velocity of dislocation due to the proximity of the dislocation line to the surface. To verify this finding, molecular dynamics simulations for an edge dislocation in bcc molybdenum are pe...

While much attention has been paid to the orientations and structures of the habit planes of various precipitates, the orientations and structures of the edge facets are less well understood. This work presents a new approach to the interpretation of edge facets. The orientations and dislocation structures of the edge facets of a precipitates in a b matrix in a Ti–7.26 wt.% Cr alloy were invest...

The general solution describing an edge dislocation inside a smectic A film is presented. Its elastic interaction energy with the limiting surfaces is calculated by taking into account ngorously the surface tension y This formula is used to discuss the dislocation stability with respect to a slip motion towards the surface If surface tension prevails over smectic A elasticity, charactenzed by e...

The problem of the collective behavior of straight parallel edge dislocations is investigated. Starting from the equation of motion of individual dislocations a continuum description is derived. It is shown that the influence of the short range dislocation-dislocation interactions on the dislocation dynamics can be well described by a local back stress which scales like the square root of dislo...

Combining through-focus high-resolution transmission electron microscopy and hierarchical multiscale simulations consisting of density-functional theory, analytical empirical potentials, and continuum elastic theory we demonstrate the existence of a new dislocation type in GaN. In contrast with all previously identified or suggested dislocation structures in GaN, all core atoms are fully coordi...

A new computer simulation method based on stochastic integration of the Langevin equations of dislocation motion is proposed for the investigation of the dynamic properties of a system of parallel straight dislocations. The stochastic approach developed for weakly correlated dislocation systems allows for more than 106 dislocations in the simulation area. Relaxation of a system of 220 parallel ...

A closed-form solution is obtained for the interfacial edge crack between two bonded dissimilar orthotropic strips loaded by antiplane point loading in form of screw dislocation or line force. Conformal mapping and existing dislocation solutions are utilized for constructing the fundamental solution of the problem. The stress intensity factor (SIF) and the energy release rate (ERR) are obtained...

The imaging conditions for weak beam (WB) studies of dislocations in Ti3AI with intermediate voltage transmission electron microscopes have been derived following a theoretical examination of the traditional criteria for WB-microscopy. The cores of <2c+a>-dislocations in room temperature deformed Ti3AI have been characterised in a case study with 300kV electrons by experimental WB-microscopy, w...