Line defects (also called dislocations) are one-dimensional (1D) imperfections in the crystal structure of a material. They represent a misalignment of atoms along a line within the crystal lattice.
These defects are crucial because they play a key role in plastic deformation—they allow materials, especially metals, to bend or stretch rather than break.
Picture an extra half-plane of atoms inserted into the crystal.
The line defect is along the edge of that plane.
Causes distortion around the edge, like a bulge in the atomic structure.
🧭 Burgers vector (a measure of lattice distortion) is perpendicular to the dislocation line.
The atomic planes are sheared, forming a spiral or "screw" shape around the dislocation line.
Imagine cutting partway through a block and twisting one side.
🧭 Burgers vector is parallel to the dislocation line.
Most real dislocations are mixed, with both edge and screw characteristics.
Different sections of the same dislocation line may behave differently.