  This model considers reversible elementary acts of migration of point defects
(interstitials and/or vacancies) across the precipitate-matrix interface and
enables one to derive equations for the rates of emission and absorption of
solute atoms at the interface. The model predicts much stronger heterophase
fluctuations and higher nucleation rates than the classical nucleation theory
does. However, asymptotically, for large precipitate sizes and long ageing
times, both models give the same results, being in agreement with the
Lifshitz-Slyozov-Wagner theory of coarsening.
