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

晶界溶质偏析及其对晶界扩散速率的影响

• 批准号: 9725047
• 负责人: Richard Yund
• 金额: $ 9.4万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-01-01 至 2002-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9725047&HistoricalAwards=false
• 关键词: Solute; Segregation; Grain; Boundaries; its

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.

9725047 Yund由镁橄榄石和斜长石组成的细粒样品，其中含有Rb、Sr和Ba等杂质。这些多晶样品将在T和P下退火（并淬火），以便在晶界区域和块体晶体之间建立平衡。将使用SEM确定块体晶体的晶界区域和相邻区域之间的组成差异。可以确定相当于晶界上单层的十分之一的溶质浓度的差异。将对上述骨料进行晶界扩散实验。将在各种温度和压力下使用稳定同位素示踪剂，并通过离子探针确定浓度分布。