Burgers Vector, b
The Burgers vector associated with a dislocation is a measure of the lattice distortion caused by the presence of the line defect. The diagram shows the convention for measuring the Burgers vector. A circuit is made around a dislocation line in a clockwise direction (top picture) with each step of the circuit connecting lattice sites that are fully coordinated. This circuit is then transferred to a perfect lattice of the same type. Because of the absence of a dislocation within this circuit, it fails to close on itself, and the vector linking the end of the circuit to the starting point is the Burgers vector, b = QM.

The Burgers vector defined in this way is a unit vector of the lattice if the dislocation is a unit dislocation, and a shorter stable translation vector of the lattice if the dislocation is a partial dislocation.