Resonance structures of divalent cations in sodium phosphate glass

This research investigates the causes of abnormal phenomena that arise when alkaline earth elements are added to sodium phosphate glass, as network modifiers, through a structure-based study. Many studies have shown that the addition of MgO and ZnO to phosphate glass induces peculiarities in the physical properties, which are attributed to the structural changes caused by the added elements. In this work, sodium phosphate glass was prepared by adding alkaline earth oxides, such as CaO, BaO and CuO, all of which exhibit an inflection point, where the density changes. Abnormalities, similar to those observed in the previous studies, were observed in these cases also. X-ray diffraction was performed to analyse the structure of the prepared glass, and it was revealed that there was no change in the crystal structure, and an amorphous phase was identified. Fourier transform infrared spectroscopy (FT-IR) confirmed the difference in the short-range order of the glass structure. However, the reason for the resonance structure, when divalent cations added, was not fully confirmed through FT-IR. X-ray photoelectron spectroscopy was conducted to further confirm the abnormality in the glass. The abnormality caused by the addition of alkaline earth elements to phosphate glass was explained based on the results of these analyses.