VIBRATIONAL STUDIES OF STRONTIUM ANTIMONY PHOSPHATE GLASS

Abstract

Glass samples in a series of 60P₂O_5-xSb₂O_3-(40-x)SrO (95-x)P2O₅-5Sb₂O_3-xSrO and (95-x)P2O_5-xSb₂O₃-5SrO with 5≤x≤35 mol% were prepared using melt-quenching technique. The effect of SrO and Sb₂O₃ content on the structure of ternary Sb₂O₃-SrO P2O5 ultraphosphate glass has been measured by means of X-ray Diffraction (XRD), Infrared and Raman Spectroscopy. The results from XRD patterns indicate that the compositions containing up to 35% of Sb₂O₃ and/or SrO formed as a glass easily and there were no crystalline phases detected. Spectra from IR and Raman Spectroscopy indicate shows the phosphate network of these glasses was composed of branching (Q3), middle phosphate tetrahedral (Q2), pyrophosphate (Q1), and other strontium/antimony anions. The occurrences of Q1 in the crystalline ultraphosphate are due to the disproportionate of the type 2Q2 ßàQ1+Q3 that occurred in these glasses. All the symmetric and asymmetric stretching vibrations of POP and PO₂ observed in the spectra are the characterization of Q3 and Q2 groups. Furthermore, the glass network, especially the Q2 unit can be modified by the SrO and Sb₂O₃ ions. This modification was primarily associated with the phosphate and the Q2 and Q3 units that were randomly distributed in the network. Spectroscopic results show that the modification of the phosphate network was higher and more flexible for the glass containing Sb₂O₃ with respect to the SrO. Formations of P-O-H bonds express the hygroscopic nature of the phosphate glass. From this study, it shows that the vibration spectroscopy (Infrared and Raman) are useful complement information about the network structure of the ultraphosphate glasses.