Glasses containing heavy metal oxides (HMO) are of inter-
est due to their wide range of applications in the area of glass
ceramics. Borate glasses containing unconventional Bi2O3 as
network former possess high refractive index, high optical ba-
sicity, extended far IR transmission and high non-linear optical
susceptibility [1e5]. The large polarizability and small field
strength of Bi
3þ in oxide glasses make them suitable for opti-
cal devices such as ultra fast all-optical switches, optical iso-
lators, optical Kerr shutter (OKS) and environmental
guidelines. B2O3 is one of the most common glass formers
According to Krogh-Moe [6] the structure of vitreous B2O3
consists of a random network of boroxol rings and BO3 trian-
gles connected by BeOeB linkages. Mozzi and Waren [7]
found that the addition of other oxides such as PbO causes
a progressive change of the boron atom coordination from 3
to 4 and results in the formation of various units like diborate
triborate, or tetraborate groups.
Fu and Yatsuda [8] investigated the glass forming regions
thermal and optical properties of Bi2O3eZnOeR2O(R ¼ Li
Na, K), Bi2O3eZnOeR0
O(R0
¼ Ca, Sr, Ba) and Bi2O3e