Disorder and Dynamics in Silicate Liquids, Glasses, and Crystals: Nuclear Magnetic Resonance Studies

stebbins9803953该计划侧重于晶体，玻璃和熔融硅酸盐和氧化物的原子尺度结构和动力学，并强调核磁共振（NMR）的应用，以获得基础数据，以帮助更好地理解和预测地球化学和地球物理学的兴趣过程。该方案的一个不同寻常的方面是在原位，高温核磁共振工作温度高达1500℃；目前正在开发将其扩展到高压（1kb）和高温（1000℃）的能力。高温下熔体结构和动力学的研究将得到重视，同时也将利用各种新的核磁共振方法，包括多核和多维技术，研究相应的淬火玻璃。对于晶体材料，重点将放在实验上，以确定水和矿物质之间特定位置的交换动力学，并使用新的核磁共振方法重新访问一些结构紊乱的问题，这些方法可以大大提高对四极性核素（如17O和27Al）的分辨率。P.I.和合作者最近购买了一种新的光谱仪，这是一种“宽口径”（89毫米）、600兆赫（14.1特斯拉磁铁）的系统，将在不久的将来安装，这将大大加强这些项目。

9803953StebbinsThis program focuses on atomic-scale structure and dynamics of crystalline, glassy, and molten silicates and oxides, and emphasizes the application of Nuclear Magnetic Resonance (NMR) to obtain fundamental data to help better understand and predict processes of interest in geochemistry and geophysics. An unusual aspect of the program is in situ, high temperature NMR work to temperatures up to 1500C; the capability to extend this to high pressures (1 kb) and temperatures (1000 C) is currently under development. High temperature research on melt structure and dynamics will be emphasized, as will studies of the corresponding quenched glasses with a variety of new NMR methods, including multinuclear and multidimensional techniques. For crystalline materials, the focus will be on experiments todetermine site-specific kinetics of exchange between water and minerals, and on the re-visiting of a number of questions of structural disorder using new NMR methods that give much improved resolution for quadrupolar nuclides such as 17O and 27Al. Most of these projects will be greatly enhanced by the recent purchase of a new spectrometer by the P.I. and collaborators, a "wide bore" (89 mm), 600 MHz (14.1 Tesla magnet) system that will be installed in the near future.