Thermodynamic properties of the BaO-Al2O3 system

Synthesis of the samples in the BaO-Al2O3 system was carried out by solid state synthesis method at the tem-perature 1250 degrees C (all samples) and 1500 degrees C (samples NN 5-10). The characterization of the samples was per-formed with the use of XRD analysis. The vaporization and thermodynamic properties of BaO-Al2O3 system at 1815 degrees C from 0.10 to 0.90 Ba mole fractions have been studied by Knudsen effusion differential mass spec-trometry.The formation enthalpies from the elements of Ba3Al2O6(s), BaAl2O4(s), BaAl12O19(s) were derived and the recommended values are the following: -3515 +/- 76, -2338 +/- 70 and -10730 +/- 25 kJ/mole respectively. The component activities, Gibbs energies of mixing and excess Gibbs energies were obtained. The thermody-namic properties of the BaO-Al2O3 system at high temperatures are characterized by the negative deviation from the ideal case.

Automated summary

Samples in the BaO-Al2O3 system were synthesized using solid state synthesis method and characterized by XRD analysis. The vaporization and thermodynamic properties of the system were studied using Knudsen effusion differential mass spectrometry, showing a negative deviation at high temperatures.