Approach to thermal properties and electronic polarizability from average single bond strength in ZnOBi2O3B2O3 glasses

The glass transition temperature (Tg), density, refractive index, Raman scattering spectra, and X-ray photoelectron spectra (XPS) for xZnO–yBi2O3–zB2O3 glasses (x=10–65, y=10–50, z=25–60 mol%) are measured to clarify the bonding and structure features of the glasses with large amounts of ZnO. The average electronic polarizability of oxide ions (αO2−) and optical basicity (Λ) of the glasses estimated using Lorentz–Lorenz equation increase with increasing ZnO or Bi2O3 content, giving the values of αO2−=1.963 Å3 and Λ=0.819 for 60ZnO–10Bi2O3–30B2O3 glass. The formation of BOBi and BOZn bridging bonds in the glass structure is suggested from Raman and XPS spectra. The average single bond strength (BMO) proposed by Dimitrov and Komatsu is applied to the glasses and is calculated using single bond strengths of 150.6 kJ/mol for ZnO bonds in ZnO4 groups, 102.5 kJ/mol for BiO bonds in BiO6 groups, 498 kJ/mol for BO bonds in BO3 groups, and 373 kJ/mol for BO bonds in BO4 groups. Good correlations are observed between Tg and BMO, Λ and BMO, and Tg and Λ, proposing that the average single bond strength is a good parameter for understanding thermal and optical properties of ZnOBi2O3B2O3 glasses.