• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>European Journal of Glass Science and Technology, PartB. Physics and Chemistry of Glasses >Differential volume changes in trigonal and tetrahedral borate units
【24h】

Differential volume changes in trigonal and tetrahedral borate units

机译：三角和四面体硼酸盐单位的体积差异变化

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

For the alkali borate systems, density trends have been used as an indicator for structural changes within a glass. With the use of high precision density data, we have been able to observe, indirectly, superstructural changes in the glass by, applying the differential volume technique used by Doweidar on various silicate and borate systems. This technique allows us to examine the differential changes of the volumes of the 3-coordinated trigonal units and the 4-coordinated tetrahedral units as a function of R (up to R< 0.6, where R is the mole ratio of alkali oxide to boron oxide). The relative volumes of the borate units are not constant in the low R region, but contain features that may correspond to short range units participating in large superstructural units. We applied this same analysis to the barium borates, and found that the trends of the unit volumes are nearly identical to those for the sodium borates, suggesting that the superstructural changes are also identical for both the alkali borate and alkaline earth borate systems. Finally, a comparison of our results with Kroeker's recent ~(11)B MAS NMR studies reveals that features in the unit volumes may correlate to changes in the abundance of the two observed tetrahedral units.
机译：对于碱金属硼酸盐系统，密度趋势已用作玻璃内部结构变化的指标。通过使用高精度密度数据，我们已经能够通过将Doweidar使用的微分体积技术应用于各种硅酸盐和硼酸盐系统来间接观察玻璃的超结构变化。该技术使我们能够检查3配比的三角单元和4配比的四面体单元的体积随R的变化（最高R <0.6，其中R是碱金属氧化物与氧化硼的摩尔比） ）。硼酸盐单元的相对体积在低R区域不是恒定的，但包含的特征可能对应于参与大型超结构单元的短程单元。我们对硼酸钡进行了同样的分析，发现单位体积的趋势与硼酸钠的趋势几乎相同，这表明碱金属硼酸盐和碱土金属硼酸盐系统的超微结构变化也相同。最后，将我们的结果与Kroeker最近的〜（11）B MAS NMR研究进行比较，发现单位体积中的特征可能与两个观测到的四面体单元的丰度变化相关。

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