### Abstract

The vaporization processes and thermodynamic properties of twenty samples in the Gd
_{2}
O
_{3}
-Y
_{2}
O
_{3}
-HfO
_{2}
system in a wide concentration range were studied by high-temperature Knudsen effusion mass spectrometry. At the temperature 2500 K the main vapor species were GdO, YO, and O. From the measured values of their partial pressures activities of the Gd
_{2}
O
_{3}
and Y
_{2}
O
_{3}
as functions of concentration were determined. The HfO
_{2}
activity was calculated by the Gibbs-Duhem integration. The resulting excess Gibbs energy function exhibited negative deviations from ideal behavior. For the optimization of the obtained thermodynamic functions of the ternary Gd
_{2}
O
_{3}
-Y
_{2}
O
_{3}
-HfO
_{2}
system the generalized Barker-Guggenheim theory of associated solutions was applied. In an alternative computing procedure the same model was used, but the optimization was based on the available literature data for the corresponding binary Gd
_{2}
O
_{3}
-Y
_{2}
O
_{3}
, Gd
_{2}
O
_{3}
-HfO
_{2}
, and Y
_{2}
O
_{3}
-HfO
_{2}
systems. Thus, the Barker lattice model may be used for estimation of the thermodynamic functions of a ternary system on the basis of the data for the corresponding binary sub-systems.

Original language | English |
---|---|

Pages (from-to) | 1207-1212 |

Number of pages | 6 |

Journal | Journal of Alloys and Compounds |

Volume | 791 |

DOIs | |

Publication status | Published - 30 Jun 2019 |

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### Scopus subject areas

- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry

### Cite this

_{2}O

_{3}-Y

_{2}O

_{3}-HfO

_{2}system studied by high temperature Knudsen effusion mass spectrometry and optimized using the Barker lattice theory.

*Journal of Alloys and Compounds*,

*791*, 1207-1212. https://doi.org/10.1016/j.jallcom.2019.03.182

}

_{2}O

_{3}-Y

_{2}O

_{3}-HfO

_{2}system studied by high temperature Knudsen effusion mass spectrometry and optimized using the Barker lattice theory',

*Journal of Alloys and Compounds*, vol. 791, pp. 1207-1212. https://doi.org/10.1016/j.jallcom.2019.03.182

**Thermodynamic properties of the Gd
_{2}
O
_{3}
-Y
_{2}
O
_{3}
-HfO
_{2}
system studied by high temperature Knudsen effusion mass spectrometry and optimized using the Barker lattice theory.** / Shilov, A. L.; Stolyarova, V. L.; Lopatin, S. I.; Vorozhtcov, V. A.

Research output

TY - JOUR

T1 - Thermodynamic properties of the Gd 2 O 3 -Y 2 O 3 -HfO 2 system studied by high temperature Knudsen effusion mass spectrometry and optimized using the Barker lattice theory

AU - Shilov, A. L.

AU - Stolyarova, V. L.

AU - Lopatin, S. I.

AU - Vorozhtcov, V. A.

PY - 2019/6/30

Y1 - 2019/6/30

N2 - The vaporization processes and thermodynamic properties of twenty samples in the Gd 2 O 3 -Y 2 O 3 -HfO 2 system in a wide concentration range were studied by high-temperature Knudsen effusion mass spectrometry. At the temperature 2500 K the main vapor species were GdO, YO, and O. From the measured values of their partial pressures activities of the Gd 2 O 3 and Y 2 O 3 as functions of concentration were determined. The HfO 2 activity was calculated by the Gibbs-Duhem integration. The resulting excess Gibbs energy function exhibited negative deviations from ideal behavior. For the optimization of the obtained thermodynamic functions of the ternary Gd 2 O 3 -Y 2 O 3 -HfO 2 system the generalized Barker-Guggenheim theory of associated solutions was applied. In an alternative computing procedure the same model was used, but the optimization was based on the available literature data for the corresponding binary Gd 2 O 3 -Y 2 O 3 , Gd 2 O 3 -HfO 2 , and Y 2 O 3 -HfO 2 systems. Thus, the Barker lattice model may be used for estimation of the thermodynamic functions of a ternary system on the basis of the data for the corresponding binary sub-systems.

AB - The vaporization processes and thermodynamic properties of twenty samples in the Gd 2 O 3 -Y 2 O 3 -HfO 2 system in a wide concentration range were studied by high-temperature Knudsen effusion mass spectrometry. At the temperature 2500 K the main vapor species were GdO, YO, and O. From the measured values of their partial pressures activities of the Gd 2 O 3 and Y 2 O 3 as functions of concentration were determined. The HfO 2 activity was calculated by the Gibbs-Duhem integration. The resulting excess Gibbs energy function exhibited negative deviations from ideal behavior. For the optimization of the obtained thermodynamic functions of the ternary Gd 2 O 3 -Y 2 O 3 -HfO 2 system the generalized Barker-Guggenheim theory of associated solutions was applied. In an alternative computing procedure the same model was used, but the optimization was based on the available literature data for the corresponding binary Gd 2 O 3 -Y 2 O 3 , Gd 2 O 3 -HfO 2 , and Y 2 O 3 -HfO 2 systems. Thus, the Barker lattice model may be used for estimation of the thermodynamic functions of a ternary system on the basis of the data for the corresponding binary sub-systems.

KW - Gadolinia

KW - Hafnia

KW - Knudsen effusion mass spectrometry

KW - Lattice model

KW - Rare earth alloys and compounds

KW - Thermodynamic modeling

KW - Yttria

KW - OXIDE SYSTEMS

KW - VAPORIZATION

UR - http://www.scopus.com/inward/record.url?scp=85063874522&partnerID=8YFLogxK

U2 - 10.1016/j.jallcom.2019.03.182

DO - 10.1016/j.jallcom.2019.03.182

M3 - Article

AN - SCOPUS:85063874522

VL - 791

SP - 1207

EP - 1212

JO - Journal of Alloys and Compounds

JF - Journal of Alloys and Compounds

SN - 0925-8388

ER -

_{2}O

_{3}-Y

_{2}O

_{3}-HfO

_{2}system studied by high temperature Knudsen effusion mass spectrometry and optimized using the Barker lattice theory. Journal of Alloys and Compounds. 2019 Jun 30;791:1207-1212. https://doi.org/10.1016/j.jallcom.2019.03.182