Solute Segregation at Grain Boundaries and its Effect on Grain Boundary Diffusion Rates

由镁橄榄石和斜长石组成的9725047个含有Rb、Sr、Ba等杂质的细晶样品将被热压。这些多晶样品将在T和P处进行退火(和淬火)，以便在晶界区域和大块晶体之间建立平衡。大块晶体的晶界区域和相邻区域之间的成分差异将使用扫描电子显微镜来确定。可以确定晶界上相当于十分之一个单分子层的溶质浓度的差异。对上述集料进行晶界扩散实验。稳定的同位素示踪将在不同的温度和温度下使用，浓度分布将通过离子探测器确定。

9725047 Yund Fine-grained samples consisting of forsterite and plagioclase saturated with impurities such as Rb, Sr and Ba will be hot-pressed. These polycrystalline samples will be annealed at T and P (and quenched) in order to establish equilibrium between grain boundary region and the bulk crystal. Compositional differences between the grain boundary region and adjacent regions of the bulk crystal will be determined using SEM. Differences in concentrations of solutes equivalent to a tenth of a monolayer on a grain boundary can be determined. Grain boundary diffusion experiments will be made on the above aggregates. Stable isotope traces will be used at a variety of T and P and concentration profiles will be determined via ion probe.