Structural study of density and refractive index of Sb2O3–B2O3 glasses

• The article presents properties–structure correlations of Sb2O3–B2O3 glasses.
• Values of N4 could be used to calculate the concentration of structural species.
• Sb2O3 is considered to build a single former species (SbO3 pyramids).
• Calculated D, Vm, μ and R agree well with the experimental data.

Density, molar volume, refractive index and molar refraction have been correlated with the structural units in Sb2O3–B2O3 glasses. It is proposed that these glasses include SbO3 pyramids, BO4 tetrahedra, symmetric- and asymmetric BO3 units. Concentration of these units could be determined by using literature data of the fraction of four-coordinated boron atoms. Each of the structural units contributes to the studied properties by a factor that remains the same overall the entire composition region. Probable existence of certain fraction of Sb5 + ions is discussed. It is deduced that the glasses can be treated by assuming the presence of SbO3 as the sole structural unit of Sb2O3.