Structure and physical properties of Bi2O3–B2O3–Ga2O3 glasses

Abstract Glasses with compositions xBi 2 O 3 –35B 2 O 3 –(65 − x)Ga 2 O 3 (x = 45, 50, 55, 60 mol%) were prepared by conventional melting method. The thermal properties were investigated by differential thermal analysis (DTA) and the structures of the glasses were probed by infrared, Raman and X-ray photoelectron spectroscopies (XPS). The results show that both density and refractive index increase with increase of Bi 2 O 3 . The glass transition temperature (T g ), onset crystallization temperature (T x ) and ΔT (T x − T g ) decrease with the content of Bi 2 O 3 . The glass network is mainly constituted by the [BiO 6 ] octahedron, [BO 3 ] triangle, [BO 4 ] tetrahedron and steady [GaO 4 ] tetrahedron structural units. Borate oxide exists mainly in [BO 3 ] units in the glass. [BO 4 ] units are converted into [BO 3 ] with increasing Bi 2 O 3 by producing more non-bridging oxygens. Raman and XPS investigation indicates that Bi 5+ ions may be formed in the glass containing 60 mol% Bi 2 O 3 .