Thermodynamic properties of the Na2O-BaO-B2O3 glasses and melts

•The glass formation region in the system Na2O-BaO-B2O3 has been established.•A region with partial crystallization has been found inside the glass formation region.•Partial pressures, components Activities, Gibbs energies and excess Gibbs energies were derived by KEMS method. The glass formation region in the system Na2O-BaO-B2O3 has been established. Thermodynamic properties for this system were derived. It is found that the lower border of glass formation region is limited to composition containing 10–30 mol.% Na2O, 10–30 mol.% BaO and 60 mol.% B2O3. A region with partial crystallization has been found inside the glass formation region. This region is limited to compounds 5 Na2O-20 BaO-75 B2O3 mol.% and 10 Na2O-20 BaO-75 B2O3 mol.%. The vaporization processes and thermodynamic properties of the Na2O-BaO-B2O3 melts were investigated by the Knudsen effusion mass spectrometry in the temperature range 1290–1750 K. The values of the component activities, Gibbs energies and excess Gibbs energies were derived from experimental data. It was shown that the studied system is characterized by a negative deviation from the ideal behavior.