Harmonic lattice theory was used, together with Mura's theory of eigen-distortions, to study the structure and energetics of nascent dislocation loops in face-centered cubic crystals. An analytical expression was derived for the activation energies of such loops. The results which were obtained indicated that thermal activation of small dislocation loops was possible at high stress levels; such as those found in the vicinity of a crack tip. This had implications for the understanding of phenomena such as the brittle-ductile transition.

The Atomistic Structure and Energy of Nascent Dislocation Loops. V.B.Shenoy, M.Ortiz, R.Phillips: Modelling and Simulation in Materials Science and Engineering, 1999, 7[4], 603-19