Vaporization and thermodynamic properties of the SrO-Al 2 O 3 system studied by Knudsen effusion mass spectrometry

• Published in: Rapid communications in mass spectrometry 2022-06, Vol.36 (12), p.e9298
• Main Authors: Lopatin, Sergey I, Shugurov, Sergey M, Tyurnina, Natalia G, Tyurnina, Zoya G, Polyakova, Irina G, Balabanova, Ekaterina A
• Format: Article
• Language: English
• ISSN: 0951-4198; 1097-0231
• DOI: 10.1002/rcm.9298

Strontium aluminates can be used as refractory construction materials at temperatures up to 2000°С or as the materials for immobilization of long-lived radioactive waste. The SrО-Al O system is one of the more complicated oxide systems used for the creation of new radio-transparent materials. The exploitation of such materials at high temperatures demands the knowledge of the thermal stability of the compounds and solid solutions formed in the SrО-Al O system. The synthesis of the samples in the SrO-Al O system was carried out by a ceramic method at 1250°C. The characterization of the samples was accomplished with the use of X-ray diffraction (XRD). The vaporization of the samples under study was performed from a twin tungsten effusion cell using the Knudsen effusion mass spectrometry method. The temperature dependences of partial pressures of vapor species over 4SrO·Al O , 3SrO·Al O , SrO·Al O , SrO·2Al O and SrO·6Al O in a wide range of temperatures were determined. The component activities, the Gibbs energies of mixing and the standard enthalpies of individual strontium aluminates were obtained. The thermodynamic properties of the SrO-Al O system at high temperatures are characterized by negative deviation from ideality. The vaporization processes and thermodynamic properties of the SrO-Al O system were obtained for the first time.