Vaporization behavior and thermodynamic properties of CeO ₂ –Al ₂ O ₃ melts

Abstract Solid solutions based on cerium dioxide are important functional materials with diverse applications, particularly in electrochemical and catalytic systems. The synthesis and application of CeO 2 ‐based systems frequently require exposure to extreme heat, leading to a selective loss of volatile components from the solid matrix. This process significantly impacts both the material's composition and performance. However, the behavior of ceria‐containing ceramics under such conditions remains poorly understood. This work focuses on investigating the thermodynamic stability of CeO 2 –Al 2 O 3 melts. Specimens were prepared via high‐temperature solid‐state synthesis (1673 K, 22.5 h) and characterized via x‐ray diffraction analysis. Vaporization of the system was studied using Knudsen effusion mass spectrometry within the 2150–2720 K range. The most stable composition at 2350 K, corresponding to the minimum Δ G m of −42.3 ± 0.7 kJ mol −1 , is located at (52% ± 2%) CeO 2 . The system displays significant negative deviation from ideality. Among the binary CeO 2 ‐based systems (with Al 2 O 3 , Gd 2 O 3 , Y 2 O 3 , and ZrO 2 as the second component), CeO 2 –Al 2 O 3 demonstrated the highest thermodynamic stability.