Role of Al2O3 in Al2O3–Bi2O3–P2O5 glasses

Research on ternary Al2O3–P2O5–Bi2O3 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 Al2O3 in the network of the explored glasses. It was found that the ultrasonic features are Al2O3 dependent. Inspections of FTIR spectra point that Al2O3 is preferably inserted into the phosphate network forming (AlO4) units, while Bi2O3 accesses the network as (BiO6) 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 Bi2O3 via high-bond strength Al2O3. The analysis reveals the former role of Al2O3.