Determination of refractive index and electronic polarisability of oxygen for lithium-silicate melts using ellipsometry
Determination of refractive index and electronic polarisability of oxygen for lithium-silicate melts using ellipsometry
复制标题
使用椭圆光度法测定硅酸锂熔体的氧折射率和电子极化率
DOI：
10.1016/s0022-3093(02)01423-0
复制
发表时间：
2003
影响因子：
3.5
通讯作者：
K. Nagata
中科院分区：
文献类型：
--
作者：
T. Yagi;M. Susa;K. Nagata
用高温椭偏仪测量了li2o - sio2熔体的折射率。在广泛的温度范围内（1300-1800 K）对四种不同成分的样品进行了测量。测量值的标准偏差在±0.0005以内。在所研究的温度范围内，发现Li2O的加入会引起折射率的增加。当Li2O浓度<25 mol%时，熔体的折射率随温度升高而升高，与SiO2相似。随着Li2O的加入，熔体的折射率随温度的升高而降低，Li2O浓度大于30 mol%时，熔体的折射率随温度的升高而降低。在洛伦兹-洛伦兹方程的基础上，从密度和摩尔电子极化率出发，讨论了折射率对温度的依赖关系。此外，由摩尔电子极化率得出的氧的电子极化率随着每次熔体温度的升高而增加，表明氧的离子性随着温度的升高而增加。此外，由于形成了非桥接氧离子，发现Li2O的加入导致氧的电子极化率增加。
The refractive index of Li2O–SiO2melts has been measured using the ellipsometer constructed for high-temperature use. Measurements were carried out on four samples having different compositions over a wide temperature range (1300–1800 K). The standard deviation for the values measured was within ±0.0005. Additions of Li2O were found to cause increases of refractive index in the temperature range investigated. At Li2O concentrations <25 mol% the refractive indices of the melts increased with increasing temperature, similar to SiO2. However, this temperature dependence became smaller with additions of Li2O and at Li2O concentrations more than 30 mol% the refractive indices of the melts decreased with increasing temperature. The temperature dependence of the refractive indices has been discussed from those of the density and the molar electronic polarisability on the basis of the Lorentz–Lorenz equation. In addition, the electronic polarisability of oxygen derived from the molar electronic polarisability increased with increasing temperature in each melt, suggesting that the ionicity of oxygen increases as temperature increases. Furthermore, additions of Li2O were found to cause increases in the electronic polarisability of oxygen, due to the formation of non-bridging oxygen ions.