Diffusion and electrical conductivity studies in some heterophase glasses containing bismuth

Abstract

Self-diffusion coefficients of sodium in the temperature range 300 to 375° C have been measured for glasses in the system Na₂O-B₂O₃-Bi₂O₃-SiO₂, by using a radioactive tracer technique. All these glasses have a two-phase structure. The d.c. resistivities of these glasses were also measured over the temperature range 30 to 375° C. The correlation factors,f, of all the samples have been calculated by using the diffusion coefficients and d.c. resistivity values for temperatures above 300° C. The anomalously large f values in the case of Bi₂O₃-containing glasses are thought to be due to a distribution of sodium ions in the dispersed as well as the continuous phases in these systems.