Thermo-Optic Properties and Electronic Polarizability in Alkali Tellurite Glasses

摘要: The refractive indices (n) and densities (ρ) of xLi2O–(100−x)TeO2 glasses with x=15–30 xNa2O–(100−x)TeO2 x=10–20 are measured in the temperature range 30°–150°C order to clarify thermo-optic coefficients (dn/dT) dependence electronic polarizability oxide ions () optical basicity (Λ). It is found that values n, , Λ increase almost linearly increasing temperature. dn/dT around 7 × 10−5 K−1 tend decrease alkali content (Li2O, Na2O). In contrast, d/dT dΛ/dT constant, irrespective content. suggested has an important contribution on coefficients, but volume thermal expansion cannot be ignored. analyses polarizabilities tellurite glasses, concept group for TeO3 TeO4 structural units also applied. explained large Li2O–TeO2 Na2O–TeO2 composed oxides having small average single bond strengths basicities.