The cBΩ model, which suggested that the defect Gibbs energy was proportional to the isothermal bulk modulus and the mean volume per atom, was first introduced in order to predict self-diffusion coefficients of oxygen in various silicate and oxide minerals in terms of available elastic data. A new approach was developed in order to determine the constant, c, in the cBΩ model on the basis of the observed compensation effect between the activation energies and pre-exponential factors, which was critical to the diffusivity prediction. Under anhydrous conditions, the validity of this model was tested by the experimentally determined oxygen self-diffusion coefficients. The results showed that the absolute oxygen diffusion rates derived from the cBΩ model were in agreement with experimental data in a variety of rock-forming minerals including olivine, MgSiO3 perovskite, spinel, and zircon.

Application of the cBΩ Model for the Calculation of Oxygen Self-Diffusion Coefficients in Minerals. B.Zhang, X.Wu, J.Xu, R.Zhou: Journal of Applied Physics, 2010, 108[5], 053505