Structure and Properties of Low Phonon Antimony Glasses in the K2O–B2O3–Sb2O3–ZnO System

The monolithic glass-forming region of the low phonon and low softening point antimony glasses containing high Sb₂O₃ (40–75 mol%) in the novel quaternary K₂O–B₂O₃–Sb₂O₃–ZnO system has been found with the help of X-ray diffraction (XRD) analysis. The structure of a series of glasses with the general composition of (mol%) 15K₂O–15B₂O₃–(70? x )Sb₂O₃– x ZnO (where x =5–25) has been evaluated by infrared reflection spectral (FT-IRRS) analyses. All the glasses are found to possess a low phonon energy of around 600 cm^?1, as revealed by FT-IRRS. Their softening point ( T _s), glass transition temperature ( T _g), and coefficient of thermal expansion (CTE) have been found to vary in the ranges of 351°–379°C, 252°–273°C, and 195–218 × 10^?7 K^?1, respectively. These properties are found to be controlled by their fundamental property, like the covalent character of the glasses, which is found to increase with an increase in Sb₂O₃ content. In addition, the devitrified glasses have been characterized by XRD and field emission scanning electron microscopy, which manifests the presence of nanozinc antimony oxide crystals with sizes of 21–43 nm. The exhibited properties have revealed that they are a new class of versatile materials.