|Lets look at a dislocation loop in cross-section. After the "cut" along the red line, the lower half was moved to the right by b. Two edge dislocation are visible if we look at a cross-section taken through the middle of the loop. A Burgers circuit now would give Burgers vectors of different signs - or does it?
|We can ask the same question in a different way: From the Volterra construction we know that the Burgers vector - including the sign - must be the same everywhere. But the dislocations shown in the cross section look "reversed" - we would certainly assign different signs just looking at the picture. How is this contradiction to be solved?
|Link to the solution
5.1.2 Volterra Construction and Consequences
Solution to Exercise 5.1-1
© H. Föll (Defects - Script)