Synthesis, vaporization and thermodynamics of ceramic powders based on the Y2O3–ZrO2–HfO2 system

Vaporization and thermodynamics of ceramics based on the La2O3‐Y2O3‐HfO2 system studied by the high‐temperature mass spectrometric method

“…Vaporization of pure Y 2 O 3 has been described previously . In the temperatures ranges 2123–2267 K 29 and 2691–2940 K 30 the main vapor species were found to be YO and O.…”

“…The vaporization processes and thermodynamic properties of the samples in the La 2 O 3 ‐Y 2 O 3 ‐HfO 2 system were studied with a MS‐1301 mass spectrometer (Institute for Analytical Instrumentation of the Academy of Sciences of USSR, Saint Petersburg, Russia) . In the present study, as was repeatedly done earlier, a molecular beam for the mass spectrometric analysis was formed using a tungsten twin Knudsen effusion cell heated by electron bombardment. In the experiments the samples were placed in one compartment of the effusion cell and another compartment of the effusion cell was loaded with a reference substance (pure La 2 O 3 or Y 2 O 3 ).…”

“…It has repeatedly been illustrated that the main vapor species over pure HfO 2 over the wide temperature range 2250–3040 K are HfO and O. The temperature dependence of the HfO partial pressures over pure HfO 2 (p o (HfO)) at 2718–3040 K was derived by us previously using the high‐temperature mass spectrometric method as: …”

“…Vaporization of pure Y 2 O 3 has been described previously. [27][28][29][30] In the temperatures ranges 2123-2267 K 29 and 2691-2940 K 30 the main vapor species were found to be YO and O. An equation for the temperature dependence of YO partial pressures over pure Y 2 O 3 (p o (YO)) was derived using the data from the thermodynamic database, 31 in the temperature range 2300-2550 K, the range over which the current investigation was carried out:…”

“…It has repeatedly been illustrated 30,32,33 The sample synthesis was carried out by the conventional solidstate method using the technique employed in our previous study. 23 The required blends of oxides were pressed into pellets under 200 bar pressure, heated to 1973 K for 6 h and held at the maximum temperature for 1 h. In contrast to the approach of Kablov et al 23 in the present study the sample pellets were allowed to cool and then ground to fine powders.…”