Question

4. (Character of dislocations) Three circular glide dislocation loops lying on a close packed plane in an FCC crystal are shown in the figure below. The Burgers vectors of the loops, which are of the type a/2 110>, are indicated by the double ended arrows (the precise Burgers vector depends on the choice of tangent vector). The magnitudes of the Burgers vectors of the loops are assumed to be the same. If the loops expand by glide, they can combine with each other to produce the heavy grey dislocation structure shown. Determine the character (sense vector, Burgers vector, half plane, etc) of each of the dislocation segments AO, BO and CO RHS +E LHS LHS ,,RHS RHS LHS

Answer 1

Sense Vector- In AO, BO, CO , the sense vector is a disjoint set.

Berger Vector- I think, there is no extra line in this given diagram so there is no burger vector.

Half Plane- If we draw a line perpendicular to AO then, according to half plane, there are one +E and two -E on one side and two +E and one -E on another side.