Intuitively, one can picture the stress fields as the stress created by adding an extra half plane of atoms to a crystal.
2.
During positive climb, the crystal shrinks in the direction perpendicular to the extra half plane of atoms because atoms are being removed from the half plane.
3.
If a vacancy moves next to the boundary of the extra half plane of atoms that forms an edge dislocation, the atom in the half plane closest to the vacancy can " jump " and fill the vacancy.
मोबाइल