Electrical Conductivity of Na2O-B2O3-SiO2-Cr2O3 Glass System

The electrical properties of glasses composed of 8Na2O-(22 - x)B2O3-70SiO2-xCr2O3, where x varies from 0.3 to 6 mol %, heat-treated at 550 degrees C for 48 h, are studied. The structure of the glasses is studied using scanning electron microscopy and X-ray powder diffraction (XRPD). It is established that in all glasses of the selected compositions, during heat treatment, an interconnected phase-separated structure is formed and the eskolaite phase (alpha-Cr2O3) also crystallizes. When comparing the obtained values of electrical resistance and activation energy of electrical conductivity of chromium-containing glasses and glass without Cr2O3 composed of 8Na2O & sdot;22B2O3 & sdot;70SiO2 and iron-containing glasses of similar compositions, it is suggested that the studied glasses with Cr2O3 possess ionic conductivity and the values of the specific volume resistance of chromium-containing and iron-containing glasses do not differ from each other. The introduction of Cr2O3 in sodium borosilicate glasses does not affect their electrical conductivity.