Thermodynamic calculations of Fe-Mg interdiffusion in (Mg,Fe)(2)SiO4 polymorphs and perovskite |
TEXT SIZE: A A A |
|
In this study, we show that the temperature and pressure dependence of Fe-Mg interdiffusion in (Fe,Mg)(2)SiO4 polymorphs (olivine, wadsleyite, and ringwoodite) and perovskite can be successfully reproduced in terms of bulk elastic and expansivity data through a thermodynamic model (so-called cB Omega model) that interconnects point defect parameters with bulk properties. Under dry and wet conditions, our calculated Fe-Mg interdiffusion coefficients D-calc(Fe-Mg) (particularly for anisotropic diffusivity in olivine), activation enthalpy h(act), and activation volume nu(act) over a wide range of geologically relevant temperatures (1000-2400K) and pressures (0-100 GPa) are consistent with the experimental ones when the uncertainties are considered. (C) 2015 AIP Publishing LLC. Publication name | JOURNAL OF APPLIED PHYSICS, 117 (5):10.1063/1.4907576 FEB 7 2015 | Author(s) | Zhang, Baohua; Shan, Shuangming | Corresponding author | SHAN Shuangming shanshuangming78@126.com Chinese Acad Sci, Inst Geochem, Key Lab High Temp & High Pressure Study Earth Int, Guiyang 550002, Guizhou, Peoples R China. | View here for the details
|
|
|
|