Defects in crystals · 2D model

How does an edge dislocation move?

Advance the dislocation one lattice spacing at a time. Watch the distorted lattice, the terminating extra half-plane, and the Burgers circuit move together along the slip plane.

Model note: This is a schematic 2D triangular lattice driven by a regularized elastic displacement field—not a bubble-raft experiment or molecular-dynamics simulation. The slider shows discrete glide positions; the field is softened near the core so the ideal elastic singularity is finite.

Triangular lattice · edge dislocation

Glide step 0 of 8
Interactive schematic of an edge dislocation gliding in a triangular lattice A triangular array of blue atoms is distorted around a dislocation core. The horizontal gold dashed line is the slip plane, and a blue dashed extra half-plane terminates at the core. Use the slider and play button to move the core.

Blue circles represent one atomic species. Bonds are nearest-neighbor guides; the dashed directions and circuit are teaching annotations.

Move the dislocation

LeftOne step = one Burgers vectorRight

The core is at the left end. Move one step to see glide along the slip plane.

What moves?

The core is where the lattice distortion is largest. In this schematic, five- and seven-neighbor sites mark the local coordination change around the core. Advancing the slider moves that distortion by one lattice spacing.

Glide plane & half-plane

The gold dashed horizontal line is the glide (slip) plane. The blue dashed line is the extra half-plane, ending at the core. As the edge dislocation glides, the extra half-plane's termination moves along the crystal.

Burgers circuit

Trace the dashed path around the core. Its endpoints do not meet: the closure gap is the Burgers vector, shown as b. Here it is parallel to the glide plane and has a magnitude of one lattice spacing.

For a reference on atomistic dislocation analysis, see OVITO's Dislocation Analysis documentation. This classroom visualization is an explanatory model, not an OVITO analysis or atomistic simulation.