...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Non-Crystalline Solids: A Journal Devoted to Oxide, Halide, Chalcogenide and Metallic Glasses, Amorphous Semiconductors, Non-Crystalline Films, Glass-Ceramics and Glassy Composites >Excited oxygen-deficient center in silicon dioxide as a structurally non-rigid, mixed-valence complex
【24h】

Excited oxygen-deficient center in silicon dioxide as a structurally non-rigid, mixed-valence complex

机译：二氧化硅中的兴奋性缺氧中心，为结构上非刚性的混合价络合物

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A possible mechanism is proposed for UV light induced refractive index change in silica glass which results from densification of the SiO2 matrix around photo-excited neutral oxygen vacancies (oxygen-deficient centers ODC). Such densification is supposed to be due to a 'local phase transition' induced by a transformation of one of the valence sp-electrons of the ODC from a localized to a partially delocalized state. Theoretically, the latter state arises in constructing the energy spectrum of a singly excited, relaxed ODC and may be interpreted as an intermediate-radius exciton-like state in the framework of the Falicov model for mixed-valence systems. It is shown that the partially delocalized state can become energetically favorable as compared to the localized one. This mechanism of the photorefractive effect eliminates the contradiction between a large refractive index change and a relatively small ODC concentration in silicas, because it does not invoke the assumption of a photo-induced change in polarizability of point defects. (C) 1998 Elsevier Science B.V. All rights reserved. [References: 18]
机译：提出了一种可能的机制，用于石英玻璃中紫外线引起的折射率变化，这是由光激发的中性氧空位（缺氧中心ODC）周围的SiO2基体致密化导致的。这种致密化被认为是由于ODC的价电子之一从局域化到部分局域化引起的“局域相变”。从理论上讲，后一种状态是在构造单激发的，松弛的ODC的能谱时出现的，并且在混合价系统的Falicov模型的框架内，可以将其解释为中间半径的激子状状态。结果表明，与局域化的状态相比，部分局域化的状态在能量上变得有利。这种光折变效应的机理消除了二氧化硅中较大的折射率变化和相对较小的ODC浓度之间的矛盾，因为它没有引用点缺陷极化率的光致变化的假设。 （C）1998 Elsevier Science B.V.保留所有权利。 [参考：18]

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号