Properties and Structures of Bi2O3–B2O3–TeO2 Glass

Abstract

Glass formation range of Bi2O3–B2O3–TeO2 system has been investigated (B2O3 ≤ 40 mol%). Four glasses with compositions xBi2O3–30B2O3–(70–x)TeO2 (x = 40, 50, 60 and 70 mol%) have been prepared by using melt quenching technique. The effect of Bi2O3 content on thermal stability, optical properties and structures of these four Bi2O3–B2O3–TeO2 glasses is systematically investigated by inductive coupled plasma emission spectrometer (ICP), differential scanning calorimetry (DSC), Raman spectra and X-ray photoelectron spectroscopy (XPS). It is found that the density, refractive index and optical basicity increase with increasing Bi2O3. The Raman spectra and XPS spectra show that the glass network is mainly constituted by the [BiO6] octahedron, [TeO4] trigonal bipyramidal, [TeO3] trigonal pyramid, [BO3] trigonal pyramid and [BO4] tetrahedron structural units. With increasing Bi2O3, the coordination number around B atom changes from 3 to 4 and [TeO4] units are converted to [TeO3] units. Bi5+ ions may exist in Bi2O3–B2O3–TeO2 (BBT) system and their amount grows with increasing Bi2O3 content.