Experimental Measurements of Grain-Boundary Diffusivities in Mantle Silicates

9315343 Graham这个项目将确定辉辉石、橄榄石和透辉石多晶的晶界扩散系数作为温度、氧逸度（使用CO/CO2混合物）和铁（透辉石中的钙）含量的函数。通过H2/H2O混合气体控制氧逸度的实验，研究了水逸度（和氢逸度）对晶界扩散率的影响。该研究将阐明晶界作为离子和电子输运管道的作用，离子和电子输运是地球科学和材料科学中的重要现象。

9315343 Graham This project will determine grain boundary diffusivities in enstatite, olivine, and diopside polycrystals as a function of temperature, oxygen fugacity (using CO/CO2 mixtures), and iron (and calcium in diopside) content. The effects of water (and hydrogen) fugacity on grain boundary diffusivity will be investigated by performing experiments using H2/H2O gas mixtures to control the oxygen fugacity. The research will elucidate the role of grain boundaries as conduits for ionic and electronic transport, which are important phenomena in both geosciences and materials sciences.