RIA: Investigation of Ion-Exchanged Glass Using Glancing Angle EXAFS

本研究计划利用掠射角扩展x射线吸收精细结构（EXAFS） x射线吸收光谱研究多组分玻璃的结构及其在掺杂物扩散下的变化。本文将研究两种玻璃的结构。在第一种“单碱”玻璃中，只有一种元素成分与掺杂剂进行离子交换。在第二种“混合碱”类型中，两种或两种以上的组分与掺杂阳离子相互作用。预计掺杂剂的扩散将沿着整个玻璃的“渗透通道”发生；对于两种玻璃类型，这些应该是不同的。此外，由于表面抛光过程中的碱浸，这些通道预计会在玻璃表面附近关闭。这项研究的结果预计将对集成光学技术、微光学和梯度折射率光学产生直接影响，所有这些技术都使用玻璃中的离子交换来制造它们的许多组件。EXAFS的测量将与达斯伯里实验室的G. N. Greaves教授合作，达斯伯里实验室是位于英国沃灵顿的一个国际同步加速器设施。

This research program uses glancing angle Extended X-ray Absorption Fine Structure (EXAFS) x-ray absorption spectroscopy to investigate the structure of multicomponent glasses and how they are changed by dopant diffusion. The structure of two types of glasses will be investigated. In the first type, a "single alkali" glass, only one elemental component participates in ion exchange with the dopant. In the second "mixed alkali" type, two or more components interact with the dopant cation. Dopant diffusion is expected to occur along "percolation channels" throughout the glass; these should be different in character for the two glass types. Further, these channels are expected to close off near the glass surface due to alkali leaching during surface polishing. The results of this study are expected to have a direct impact on integrated optics technology, micro-optics and gradient-index optics, all of which use ion exchange in glass for fabrication of many of their components. The EXAFS measurements will be in collaboration with Professor G. N. Greaves of the Daresbury Laboratory, an international synchrotron facility in Warrington, England.