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For line tangent $\mathbf{t}$, a screw dislocation has Burgers vector parallel to $\mathbf{t}$, an edge dislocation has it perpendicular, and a mixed dislocation has both components.

A mixed dislocation has a line direction neither parallel nor perpendicular to its Burgers vector, combining screw and edge character. Along a curved dislocation line, the local character can change continuously while the Burgers vector remains fixed.

A dislocation loop therefore need not be assigned one character everywhere. Decomposing a local segment into edge and screw contributions helps analyze its stress field, mobility, and interaction with obstacles.