Study on structural relaxation in silica glass

研究石英玻璃的结构弛豫对于开发具有超低损耗和抗紫外线等高性能的石英玻璃是必要的。二氧化硅玻璃由于结构简单，也有利于玻璃化转变机理的研究。在本项目中，我们尝试测量了包括玻璃转变温度在内的广泛温度范围内石英玻璃的各种性质，并阐明了结构驰豫过程及其杂质效应如下：(1)OH或Cl增强了由粘性流动控制的α-驰豫过程，并产生了亚弛豫过程。(2)亚驰豫过程是由杂质扩散引起的局部结构变化。(3)我抑制了α-驰豫，而不是OH和Cl.根据这些结果，我们建立了通过杂质掺杂来控制结构驰豫的方法。并研制了以下高功能石英玻璃：(1)掺钠超低损耗玻璃(2)掺L超耐热玻璃(3)经OH掺杂、紫外激光照射、热退火而成的抗紫外线玻璃

Investigations of structural relaxation in silica glass are necessary for developing silica glasses with high performances such as ultralow-loss and UV-proof properties. Silica glass is also advantageous for studying on glass transition mechanism because of its simple structure. In this project we tried to measure various properties of silica glasses over a wide-temperature range including the glass transition temperature, and have elucidated structural relaxation processes and their impurity effects as follows :(1)OH or Cl enhances the alpha-relaxation governed by viscous flow, and also generates a sub-relaxational process.(2)he sub-relaxational process is local structural change caused by impurity diffusion.(3)I restrains the alpha -relaxation, contrary to OH and Cl.From these results, we have established controlling the structural relaxation by impurity doping, and developed the following high-functional silica glasses.(1)Na-doped ultralow-loss glass(2)l-doped ultra-heat-proof glass(3)Ultra UV-proof glass created by OH doping, UV-laser irradiation, and thermal annealing