High-precision Monte Carlo simulations were used to investigate tracer diffusion kinetics for diffusion via divacancies in the bcc lattice. mechanisms originally identified by Mehrer were used in which the divacancy could move by nearest-neighbor jumping, with stable first-nearest neighbor, second-nearest neighbor and fourth-nearest neighbor configurations of the divacancy. The tracer correlation factor and the 'impurity-form' correlation factor were found to be some 4 to 6% lower than those found by using the matrix method. The tracer diffusion data and isotope effect for sodium were revisited in terms of monovacancy and divacancy contributions. The main change was an upwards revision from 0.55 to 0.61 of the kinetic factor for divacancies.

Diffusion Kinetics for Divacancies in the BCC Lattice. I.V.Belova, D.S.Gentle, G.E.Murch: Philosophical Magazine Letters, 2002, 82[1], 37-41