Epitaxial Ba0.6Sr0.4TiO3 films were grown onto ~001! LaAlO3 by pulsed-laser deposition, and the dislocation structures of the films were investigated using transmission electron microscopy. Misfit dislocations with a periodicity of about 7 nm and Burgers vectors b5a^100& were observed at the interface. A high density of threading dislocations was present the films and these also had b 5a^100& ....

We propose and analyze a simple variational model for dislocations at semi-coherent interfaces. The energy functional describes the competition between two terms: a surface energy induced by dislocations and a bulk elastic energy, spent to decrease the amount of dislocations needed to compensate the lattice misfit. We prove that, for minimizers, the former scales like the surface area of the in...

We study the existence of dislocations in an anisotropic Swift-Hohenberg equation. We find dislocations as traveling or standing waves connecting roll patterns with different wavenumbers in an infinite strip. The proof is based on a bifurcation analysis. Spatial dynamics and center-manifold reduction yield a reduced, coupled-mode system of differential equations. Existence of traveling dislocat...

We consider a variational antiplane lattice model and demonstrate that at zero temperature, there exist locally stable states containing screw dislocations, given conditions on the distance between the dislocations and on the distance between dislocations and the boundary of the crystal. In proving our results, we introduce approximate solutions which are taken from the theory of dislocations i...

DISLOCATION of the scaphoid is a rare injury of which only a few reports of its occurrence appear in the literature. These include Higgs (1930), two cases; Buzby (1934); Kuth (1939); Wood-Walker (1943); Schlossbach (1954) and Connell & Dyson (1955), all reporting single cases. Russell (1949), in a review of intercarpal dislocations and fracture dislocations reported only one case of dislocation...

The movement of dislocations in a crystal is the key mechanism for plastic deformation in all materials. Studies of dislocations have focused on three-dimensional materials, and there is little experimental evidence regarding the dynamics of dislocations and their impact at the atomic level on the lattice structure of graphene. We studied the dynamics of dislocation pairs in graphene, recorded ...

Plasticity in magnesium crystals oriented for c-axis compression has been usually attributed to 〈cþa〉 dislocation slip on second-order pyramidal {112̄2} planes. Through molecular dynamics simulations, we investigated the formation and slip characteristics of 〈cþa〉 dislocations on second-order pyramidal planes. It is shown that the critical c-axis compressive stress for these dislocations is almo...

This review on elbow dislocations describes ligament and bone injuries as well as the typical injury mechanisms and the main classifications of elbow dislocations. Current treatment concepts of simple, that is, stable, or complex unstable elbow dislocations are outlined by means of case reports. Special emphasis is put on injuries to the medial ulnar collateral ligament (MUCL) and on posttrauma...