Thermodynamical stability conditions for the occurrence of hollow cores caused by stress of line and planar defects

A general stress function for screw or edge dislocations is presented and discussed. Upon introducing this stress function into a formalism to check the stability of hollow cores around dislocations, it turns out that several cases can be distinguished. If the stress field is strong enough there may or may not exist a thermodynamical stable hollow core, depending on the driving force. Above a critical super- or undersaturation Δμ ∗ 1 the hollow core will be closed, below a critical undersaturation Δμ ∗ 2 the hollow core is replaced by a steep etchpit. If, on the other hand, the stress field is too weak hollow cores do not occur. A few examples of observed hollow cores, demonstrating the theory will be presented.