Kablov Eugene N, Shilov Andrey L, Stolyarova Valentina L, Vorozhtcov Viktor A, Karachevtsev Fedor N, Lopatin Sergey I, Shugurov Sergey M
All-Russian Scientific Research Institute of Aviation Materials of the National Research Center «Kurchatov Institute», Moscow, Russia.
Grebenshchikov Institute of Silicate Chemistry of the Russian Academy of Sciences, Saint Petersburg, Russia.
Rapid Commun Mass Spectrom. 2022 Jul 15;36(13):e9306. doi: 10.1002/rcm.9306.
Materials based on the Gd O -ZrO -HfO system are promising for a wide range of high-temperature technological applications, such as for obtaining thermal barrier coatings in the aviation and space industry, as well as advanced materials in nuclear power applications. Experimental studies of the ceramics based on this system by the Knudsen effusion mass spectrometric method provides such valuable information as the vapor composition over the samples and enables derivation of the thermodynamic functions.
Samples of ceramics in the Gd O -ZrO -HfO system were synthesized and analyzed by X-ray fluorescence and diffraction techniques. The vaporization processes and partial pressures of the vapor species over the samples were obtained by the high-temperature mass spectrometric method using the ion current comparison method. The derived thermodynamic functions were optimized within the Generalized Lattice Theory of Associated Solutions (GLTAS) approach.
At the temperature of 2600 K, the GdO, ZrO, ZrO , HfO, and O vapor species were found over the samples, but only for the GdO and ZrO species were accurate experimental data on the partial pressures obtained. In all the ceramic samples, the Gd O activity was determined. On this experimental basis, modeling within the GLTAS approach was performed. It allowed the evaluation of the Gd O , ZrO , and HfO activities in the system under study and a rough approximation of the excess Gibbs energy as a function of composition to be obtained.
At 2600 K the Gd O -ZrO -HfO system is characterized by negative deviations of its thermodynamic properties from the ideal behavior. Consistency of the obtained modeling results indicate reasonable uniformity of the energy parameters of the lattice model derived in calculations of the hafnia-containing oxide systems, which may be used in further modeling of multicomponent systems.
基于Gd₂O₃-ZrO₂-HfO₂体系的材料在广泛的高温技术应用中具有广阔前景，例如在航空航天工业中用于获得热障涂层，以及在核电应用中作为先进材料。通过克努森喷射质谱法对基于该体系的陶瓷进行实验研究，可提供诸如样品上方蒸汽成分等有价值的信息，并能推导热力学函数。
合成了Gd₂O₃-ZrO₂-HfO₂体系的陶瓷样品，并通过X射线荧光和衍射技术进行分析。使用离子电流比较法，通过高温质谱法获得样品上方蒸汽物种的蒸发过程和分压。在缔合溶液广义晶格理论（GLTAS）方法内对推导的热力学函数进行优化。
在2600 K的温度下，在样品上方发现了GdO、ZrO、ZrO₂、HfO和O蒸汽物种，但仅获得了GdO和ZrO物种分压的准确实验数据。在所有陶瓷样品中测定了Gd₂O₃的活度。在此实验基础上，在GLTAS方法内进行了建模。这使得能够评估所研究体系中Gd₂O₃、ZrO₂和HfO₂的活度，并获得过量吉布斯自由能随成分变化的粗略近似值。
在2600 K时，Gd₂O₃-ZrO₂-HfO₂体系的热力学性质表现出与理想行为的负偏差。所获得的建模结果的一致性表明，在含氧化铪体系的计算中得出的晶格模型的能量参数具有合理的一致性，可用于多组分体系的进一步建模。
