Fe–Mg diffusion in olivine II: point defect chemistry, change of diffusion mechanisms and a model for calculation of diffusion coefficients in natural olivine

Diffusion creep of dry, melt-free olivine

[1] Deformation experiments were conducted on fine-grained (3–6 mm), fully synthetic Fo90 olivine aggregates in a gas-medium apparatus at 300 MPa confining pressure and temperatures of 1150–1360 C. The strain rates of the solution-gelation-derived and therefore genuinely melt-free, dry samples are about two orders of magnitude lower than the strain rates for nominally melt-free aggregates at th...

Solutions of diffusion equation for point defects

An analytical solution of the equation describing diffusion of intrinsic point defects in semiconductor crystals has been obtained for a one-dimensional finite-length domain with the Robin-type boundary conditions. The distributions of point defects for different migration lengths of defects have been calculated. The exact analytical solution was used to verify the approximate numerical solutio...

Diffusion and mobility of electrically conducting defects in olivine

Electrical conductivity of lherzolite (65% olivine), measured as a function of time after changes in the oxygen fugacity (fo2) of the surrounding CO2/CO atmosphere, is used to infer the diffusivity of the point defects responsible for conduction in olivine. A total of 63 equilibration runs at temperatures of 900, 1000, 1100, and 1200 C were fit using nonlinear parameter estimation to recover ti...

Diffusion-driven magnesium and iron isotope fractionation in Hawaiian olivine

Parameters for point-defect diffusion and recombination

Point-defect kinetics are important for understanding and modeling dopant diffusion in silicon. This paper describes models for point-defect transport and recombination used in SUPREM-IV, and does extensive fitting for the model parameters. The experimental data used are from experiments on oxidation-enhanced diffusion (OED). Interstitial traps are shown to be critical for consistent agreement ...