Application of the cBΩ model for the calculation of oxygen self-diffusion coefficients in minerals

Abstract

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

Diffusion in garnet: a review

“…To date, numerous studies have shown that the MNR is upheld not only for many diffusing species in individual minerals (Hart 1981), but also for a single diffusing species in a wide variety of minerals (Béjina and Jaoul 1997;Zheng and Fu 1998;Zhao and Zheng 2007;Zhang et al 2010Zhang et al , 2011Brady and Cherniak 2010;Jones 2014;Zhang and Shan 2015a, b). Recently, based on the observed MNR, a thermodynamic model (the so-called cBX model) has been successfully applied to predict diffusion coefficients of various elements in silicate minerals (Zhang et al , 2011Zhang 2012;Zhang and Shan 2015a, b).…”

Germanium diffusion in aluminium: connection between point defect parameters with bulk properties

“…In the single experimental measurement method the calculated value of will be affected on the errors in the preexponential factor, B, Ω, and D1 values, and these can be significant when a single experimental values set is considered. To validate the present results and avoid the dependence of on the experimental uncertainties the mean value method is also considered here [38][39][40][41][42][43]. As mentioned previously the linear behaviour of …”

“…As discussed in previous studies the method of the single experimental measurement (refer to [14,15] and references therein) is not unique and methods such as the so-called compensation law [38,39] and the "mean value" method (MV) [40][41][42] have been used to calculate . In the single experimental measurement method the calculated value of will be affected on the errors in the preexponential factor, B, Ω, and D1 values, and these can be significant when a single experimental values set is considered.…”

Toward Defect Engineering Strategies to Optimize Energy and Electronic Materials

“…Finally, it should be considered that experimental and computational techniques can be used in conjunction with established thermodynamic models, such as the cBΩ model by Varotsos and Alexopoulos, to study defect processes to design advanced energy and electronic materials [103][104][105][106][107][108][109][110][111]. In the cBΩ model, the defect Gibbs energy is assumed to be proportional to the isothermal bulk modulus (B) and the mean volume per atom (Ω).…”