Abstract
Research on ternary Al
2
O
3
–P
2
O
5
–Bi
2
O
3
glasses had been achieved. The changes in density and ultrasonic velocities were used to determine the elastic moduli and Debye temperature of the glasses. The investigated ultrasonic parameters were correlated with the structural variations represented by the FTIR spectra to examine the function of Al
2
O
3
in the network of the explored glasses. It was found that the ultrasonic features are Al
2
O
3
dependent. Inspections of FTIR spectra point that Al
2
O
3
is preferably inserted into the phosphate network forming (AlO
4
) units, while Bi
2
O
3
accesses the network as (BiO
6
) units merely. Moreover, the variations of the structure and the elastic moduli were inferred according to the oscillations of aluminates, bismuthate, and phosphate structural units on one side and the substitution of low-bond strength Bi
2
O
3
via high-bond strength Al
2
O
3
. The analysis reveals the former role of Al
2
O
3
.