Abstract :
We analyzed the thermodynamic data of the binary system Bi2O3-B2O3. The phase diagram contains five compounds, of which four melt congruently, and a miscibility gap, close to pure B2O3. The three sets of transformation data of Bi2O3, the enthalpy of mixing data in the liquid, and the critical point of the miscibility gap gave five equations for the excess Gibbs energy of mixing and five sets of values for the enthalpies of formation of the binary compounds. The critical point data yielded another set of transformation data for Bi2O3. Using the monotectic composition and the enthalpy of mixing data also yielded a set of transformation data for Bi2O3. The values obtained using the enthalpy of mixing data are the most reliable values.
