Thermal Equilibrium Kinetics of Interacting Point Defects

The local kinetics of an interacting defect species is treated on the assumption that local thermal equilibrium prevails, and a thermal equilibrium diffusion coefficient appropriate to any locality is derived in its general form. The annealing of an interacting defect species to sinks in the lattice is then shown to be identical with that of noninteracting defects having a diffusion coefficient $D_{\mathrm{eff}}=\frac{\Sigma \stackrel{}{n\alpha }n{c_{n\alpha }}^0{D}_{n\alpha }}{\Sigma \stackrel{}{n\alpha }n{c_{n\alpha }}^0},$ where ${c_{n\alpha }}^0$ is the concentration far from the sink of an $n\mathrm{th}$ order cluster of type $\alpha$, and $D_{n\alpha }$ is its diffusion coefficient. The importance of the particular case when ${c_{n\alpha }}^0$ achieves the thermal equilibrium value ${c_{n\alpha }}^t$, is noted, and the range of applicability of this diffusion coefficient is discussed.