Mechanical and structural studies on sodium borosilicate glasses doped with Er2O3 using ultrasonic velocity and FTIR spectroscopy

Sodium borosilicate glasses doped with different mol% content of Er2O3 have been prepared by rapid-quenching method. Ultrasonic velocities (both longitudinal and shear) measurements have been carried out at room temperature and at ultrasonic frequency of 4 MHz. Elastic moduli, Debye temperature, softening temperature, and Poisson's ratio have been obtained as a function of Er2O3 modifier content. Results show that the above-mentioned parameters have very slight change with the change of Er2O3 mol% content. Based on FTIR spectroscopy and theoretical (bond compression) model, quantitative analysis has been carried out in order to obtain more information about the structure of these glasses. The study indicated that the structure of these glasses is mainly composed of SiO4 units with four bridging oxygens (Q4), and with three bridging and one nonbridging oxygens (Q3).