An analysis was presented for the homogeneous nucleation of a dislocation loop under stress in a perfect crystal. By using a variational boundary integral method, within the Peierls-Nabarro framework, the saddle-point configurations of embryonic dislocation loops were determined; together with their associated activation energies under stress levels up to the ideal shear strength. The high-energy barriers under the usual levels of applied shear stresses, which differed markedly from the ideal shear strength, confirmed the view that thermal motion should play no role in such nucleation. The result provided a means for the more definitive solutions of fundamental problems which involved the homogeneous nucleation of dislocation loops. It had significant implications for models which were based upon the nucleation of dislocations in a perfect crystal.

Homogeneous Nucleation of Dislocation Loops under Stress in Perfect Crystals. G.Xu, A.S.Argon: Philosophical Magazine Letters, 2000, 80[9], 605-11