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The concept of optical basicity proposed by Duffy has been recognized as an extremely important issue in science and technology of glasses. In this article, the refractive index (n o )-based optical basicity Λ(n o ) of some binary and ternary silicate glasses was evaluated using the Lorentz-Lorenz formula, and the discrepancy between the values of Λ(n o ) and the theoretically calculated optical basicity Λ th was analyzed to understand more deeply the electronic polarizability in binary and ternary silicate glasses. A suitable value of the optical basicity for each oxide predicting a good quantitative composition dependence of optical basicity in a given glass system was proposed. The suitable value of SiO 2 for the prediction of the optical basicity of silicate glasses is Λ(SiO 2 glass) = 0.53, which is larger than the value of Λ(SiO 2 oxide) = 0.48 being used in the calculation of Λ th so far. Other suitable values such as Λ(Al 2 O 3 glass) = 0.62 and Λ(TiO 2 glass) = 1.04 were proposed. The relationship between the optical basicity and coordination structure in some oxides in silicate glasses was discussed.

The volume thermal expansion coefficients (¢) in 50300°C of xZnOyBi 2 O 3 zB 2 O 3 glasses (x = 1065, y = 10 50, z = 2560 mol %) were measured and the refractive index-based interionic interaction parameters A(n o ) were estimated from oxide ion electronic polarizabilities to acquire deeper insight into the relationship between the electronic polarizability and chemical bonding state of oxide glasses. The glasses have relatively large values of ¢ = 210289 © 10 ¹7 K ¹1 , and the substitution of ZnO for B 2 O 3 and the increase in Bi 2 O 3 content result in an increase in ¢. The values of A(n o ) decrease with the substitution of ZnO for B 2 O 3 and the substitution of Bi 2 O 3 for ZnO. An almost linear correlation was observed between ¢ and A(n o ), i.e., the volume thermal expansion coefficient decreases with increases in the interionic interaction parameter. A good correlation was also observed between A(n o ) and the refractive index-based optical basicity ª(n o ). The interionic interaction parameter is helpful for understanding the chemical bonding state of oxide glasses.

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The high temperature synthesis of glasses in the system (100‐x)(0.16Na2O/0.10CaO/0.74SiO2)/xFe2O3, x = 5 ÷ 20 mol% is reported. For Fe2O3 concentrations ≤15 mol%, glasses are formed while the sample with 20 mol% crystallizes during cooling the melt. X‐ray diffraction shows the crystallization of magnetite. The microstructure of the glass‐crystalline sample is investigated by optical microscopy and scanning electron microscopy and two types of iron‐rich crystals corresponding to magnetite and hematite are detected. The refractive indices as determined by the Becke line method are in the 1.567 ‐ 1.639 range and. increase with increasing Fe2O3 concentration. The structure is characterized using Infra‐red spectroscopy. The presence of symmetric stretching, asymmetric stretching and bending vibrations of Si‐O‐Si is detected and attributed to the occurrence of SiO4 tetrahedral units with varying numbers of nonbridging oxygens. Also, the increasing Fe2O3 concentration results in occurrence of Fe‐O‐Si bonds indicating the glass network depolymerization due to Fe2O3 addition. In all samples, the presence of Fe3+ and Fe2+ and the existence of iron ions in tetrahedral and octahedral coordination, as well as a very small amount of Fe0 and the precipitation of hematite and magnetite in the glass‐crystalline sample is revealed by Mössbauer spectroscopy.

The rapid development of telecommunication and information technology aims to design and investigate new functional materials. Glasses in the TeO2-BaO-V2O5 seems to be promising materials within this purpose. In this connection the structure and dielectric properties of the glasses have been studied. Small polaron hopping of V4+ to V5+ ion in the vanadate chains and the influence of BaO and TeO2 on the dielectric permittivity, dielectric losses and frequency depended conductivity of the glasses measured at room temperature in the frequency range from 100 Hz to 1 MHz have been discussed.