Bi precipitates in Na2O-B2O3 glasses

Bi particles of different sizes were produced in Na2O-B2O3 glasses by melt quenching and heat treatment technique. Melting temperature of Bi particles was measured by differential scanning calorimetry and X-ray diffraction. Measured melting temperatures of Bi particles are lower than bulk Bi melting temperature. Results of transmission electron microscopy were analyzed for the dependence of melting temperature on particle radius. The pressure and surface energy effect on melting temperature is estimated. The melting behavior of Bi particles in Na2O-B2O3 glasses depends on the difference in the interfacial energies between the solid particle/glass and liquid particle/glass, and liquid particle/glass, sigma(sm)-sigma(lm) which is estimated to be 255 x 10(-3) J m(-2).