Structure and crystallization behavior of binary silver tellurite glasses and glass ceramics

Abstract

Using Raman spectroscopy in conjunction with X-ray diffraction (XRD), transmission electron micrographs (TEM-EDP), and scanning electron microscopy (SEM), the local environment of Te atoms and the crystallization behavior of glasses in the system of chemical formula xAg2O. (100 − x)TeO2 (25 ≤ x ≤ 50 mol%) have been examined. Crystalline structure was evident in the XRD spectra of glasses containing 40 and 50 mol% TeO2. On the other hand, an amorphous structure has been observed in glasses with lower Ag2O concentrations (25, 30, and 35 mol%). Thermal heating could be used to crystallize the amorphous glasses’ structure. Using DSC measurements, the treatment's temperature was controlled. The species with good crystallinity include Ag2Te4O9 and Ag2Te2O5. The results of TEM and EDP, as well as both SEM and XRD, revealed that in glasses enriched with Ag2O, crystalline clustered species were formed. Raman data proved that the crystalline clustered is improved as a result of the formation of TeO3 units enriched with nonbridging oxygen bonds. In compositions containing less than 40 mol%, Ag2O plays the role of a glass modifier. At higher Ag2O concentrations, it plays the role of building crystalline clusters of the Ag2Te4O9 and Ag2Te2O5 types.