Vaporization and thermodynamics of ceramics in the Sm 2 O 3 ‐Y 2 O 3 ‐HfO 2 system
Rationale
The Sm 2 O 3 ‐Y 2 O 3 ‐HfO 2 system holds promise for applications in the sphere of high‐temperature technologies, particularly the development of ultra‐high‐temperature ceramics. However, the reliability of refractory materials is dependent on the possible selective vaporization of their components leading to changes in their physicochemical properties. Thus, information about vaporization processes and thermodynamic properties of ceramics based on the Sm 2 O 3 ‐Y 2 O 3 ‐HfO 2 system may be of importance for the production of high‐temperature materials as well as for the prediction of the physicochemical properties of ultra‐high‐temperature ceramics.
Methods
The Knudsen effusion mass spectrometric method was used, with an MS‐1301 magnetic mass spectrometer equipped with a tungsten twin effusion cell used to examine the samples in the Sm 2 O 3 ‐Y 2 O 3 ‐HfO 2 system. Electron ionization of vapor species effusing from the cell was carried out at an ionization energy of 25 eV.
Results
It was shown that at a temperature of 2373 K, selective vaporization of Sm 2 O 3 and Y 2 O 3 occurred in the samples of the Sm 2 O 3 ‐Y 2 O 3 ‐HfO 2 system, with the main vapor species being SmO, Sm, YO, and O. The partial pressures of these vapor species were obtained by the ion current comparison method. The Sm 2 O 3 activities in the Sm 2 O 3 ‐Y 2 O 3 ‐HfO 2 system were determined and allowed the evaluation of the excess Gibbs energies at 2373 K. The direction of change of the condensed phase of the samples because of selective vaporization of the components was examined.
Conclusions
The Sm 2 O 3 ‐Y 2 O 3 ‐HfO 2 system was characterized by negative deviations from the ideal behavior at 2373 K. The excess Gibbs energies evaluated in the present study were approximated using the Redlich‐Kister representation and visualized in the form of curves of constant values in the concentration triangle. The data obtained in the Sm 2 O 3 ‐Y 2 O 3 ‐HfO 2 system were optimized using the Barker‐Guggenheim theory of associated solutions.
Top-30
Journals
|
1
2
3
4
|
|
|
Russian Journal of Inorganic Chemistry
4 publications, 22.22%
|
|
|
Rapid Communications in Mass Spectrometry
3 publications, 16.67%
|
|
|
Materials Today Communications
2 publications, 11.11%
|
|
|
Russian Chemical Bulletin
1 publication, 5.56%
|
|
|
Journal of Alloys and Compounds
1 publication, 5.56%
|
|
|
Optical Materials: X
1 publication, 5.56%
|
|
|
Journal of Physics and Chemistry of Solids
1 publication, 5.56%
|
|
|
Technical Physics
1 publication, 5.56%
|
|
|
Theoretical Foundations of Chemical Engineering
1 publication, 5.56%
|
|
|
Steel Research International
1 publication, 5.56%
|
|
|
Acta Astronautica
1 publication, 5.56%
|
|
|
Russian Chemical Reviews
1 publication, 5.56%
|
|
|
1
2
3
4
|
Publishers
|
1
2
3
4
5
6
|
|
|
Elsevier
6 publications, 33.33%
|
|
|
Pleiades Publishing
6 publications, 33.33%
|
|
|
Wiley
4 publications, 22.22%
|
|
|
Springer Nature
1 publication, 5.56%
|
|
|
Autonomous Non-profit Organization Editorial Board of the journal Uspekhi Khimii
1 publication, 5.56%
|
|
|
1
2
3
4
5
6
|
- We do not take into account publications without a DOI.
- Statistics recalculated weekly.