Influence of the composition and structure of sodium borosilicate glasses on the optical-color characteristics of chromium aventurine glass in the presence of cobalt (II) oxide

Abstract

We investigated the influence of cobalt (II) oxide additive in the amount of 1–3 mol.% on the structure and optical-color characteristics of chromium-containing glass with the following composition (mol.%): 29.6 Na2O; 19.7 В2О3; 49.3 SiO2; and 1.5 Cr2O3. The dependence of the optical-color characteristics of the glasses under study on the thermal treatment of the glass melt at a temperature of 10500C for 20 minutes was established. The thermal treatment resulted in the volumetric crystallization with the subsequent development of the aventurine effect. According to X-ray phase analysis data, the decorative effect was caused by Cr2O3 crystals. By using IR spectroscopy and differential thermal analysis, the structure of the experimental glasses was studied, and the influence of thermal treatment of glass melts on the formation of the structure of glass-ceramic material was established. Aventurine glass of dark blue-green color was obtained with a color tone =490 nm, color purity P=11.35%, and lightness L=5.454 %. The nature of the influence of cobalt (II) oxide on the optical-color characteristics of chromium-containing aventurine glass based on the Na2O–В2О3–SiO2 system is of interest for further development of new compositions of decorative ceramic glazes and enamel coatings.