phase equilibria, phase diagram, solid solution, lattice parameters, functional ceramics


Using recently published scientific literature, been being provided that scientists around the world have grown increasingly interested in materials based on cerium oxide doped with rare earth metal oxides. The undeniable fact of that the study of phase equilibria of multicomponent oxide systems is both the physical and chemical basis for novel improved materials design. Among the important tasks in the study of phase equilibria of multicomponent systems is to determine the stability limits of solid solutions in a certain temperature and concentration range as well as to confirm the existence of ordered phases. In the present work, the phase equilibria of the ternary system CeO2-La2O3-Dy2O3 were investigated in the whole concentration range. The performed work was to construct an isothermal cross-section of the phase diagram CeO2-La2O3-Dy2O3 ternary system at 1100 °C. The obtained results indicate the absence of the formation of new phases in the studied system under the used technological conditions. By the method of XRD, it was determined that the formation of solid solutions based on the (F) modification of CeO2 with a fluorite-type structure, as well as monoclinic (B) and hexagonal (A) modifications of rare earth oxides, is observed in the studied system. The values of the lattice unit cell parameters of solid solutions formed in the ternary CeO2-La2O3-Dy2O3 system at a temperature of 1100 °C were analyzed. From the obtained data, it can be concluded that the lattice unit cell parameters of cubic solid solutions formed in the studied system change linearly following Wegard's law. The formation of a cubic solid solution with a fluorite-type structure F-CeO2 results in the replacement of tetravalent Ce4+ ions with trivalent Ln3+ ions. As a result, there is an increase in the unit cell parameter for cubic solid solutions with a fluorite-type structure, since the replacement occurs with ions with a larger ionic radius.


Polychronopoulou, K., Dabbawala, A. A., Sajjad, M., Singh, N., Anjum, D. H., Baker, M. A., Charisiou, N.D., Goula, M.A. (2022). Hydrogen production via steam reforming of glycerol over Ce-La-Cu-O ternary oxide catalyst: An experimental and DFT study. Applied Surface Science, 586, 152798.

Siakavelas G. I., Charisiou, N. D., lKhoorid, A. A., Sebastian, V., Hinder, S. J., Baker, M. A., Yentekaki, I. V., Polychronopoulou, K., Goula, M. A. (2022). Cerium oxide catalysts for oxidative coupling of methane reaction: Effect of lithium, samarium and lanthanum dopants. Journal of Environmental Chemical Engineering, 10(2), 107259.

Zinatloo-Ajabshir, S. (2022). 3-Rare earth cerate (Re2Ce2O7) ceramic nanomaterials. Advanced Rare. Earth-Based Ceramic Nanomaterials, 47–54.

Zeng, S., Wang, Z., Xitang, Y. M., Hao, W., Yunji, L., Yueying, D., Qiao, L. E., Qian, W. (2022). Effect of lanthanum content on the thermophysical properties and near-infrared reflection properties of lanthanum-cerium oxides. Solid State Sciences, 124, 106805.

Aponte, Á. G., Ramírez, M. A L., Mora, Y. C., Marín, J. F S., Sierra, R. B. (2020). Cerium oxide nanoparticles for color removal of indigo carmine and methylene blue solutions. AIMS Materials Science, 7(4), 468–485.

Yang, C., Lu, Y., Zhang, L., Kong, Z., Yang, T., Tao, L., Zou, Y., Wang, S. (2021). Defect Engineering on CeO2-Based Catalysts for Heterogeneous Catalytic Applications. Small Strictures, 2(12), 2100058.

Lu, G., Zheng, H., Lv, J., Wang, G., Huang, X. (2020). Review of recent research work on CeO2-based electrocatalysts in liquid-phase electrolytes. Journal of Power Sources, 480, 229091.

Li, T., Tsyshevsky, R., McEntee, M., Durke, E. M., Karwacki, C., Rodriguez, E. E., Kuklja, M. M. (2022). Aliovalent-Doping Effects on the Surface Activity of Mesoporous CeO2 toward Nerve Agent Simulant DMMP Decomposition. The Journal of Physical Chemistry C, 126(42), 17923–17934.

Lavrynenko, O. M., Zahornyi, M. M., Vember, V. V., Pavlenko, O. Y., Lobunets, T. F., Kolomys, O. F., Povnitsa, O. Y., Artiukh, L. O., Naumenko, K. S., Zahorodnia, S. D., Garmasheva, I. L. (2022). Nanocomposites Based on Cerium, Lanthanum, and Titanium Oxides Doped with Silver for Biomedical Application. Condensed Matter, 7(3), 45.

Vember, V. V., Lavrynenko, O. M., Zahornyi, M. M., Pavlenko, O. Y., Benatov, D. E. (2022). Study of the Biological Activity of Nanoparticles of Lanthanum, Cerium and Titanium Oxides and their Composites Modified with Silver. Bulletin of NTUU "KPI named after Ihor Sikorskyi". Series: Chemical engineering, ecology and resource conservation, 2, 79–87.

Asati, A., Santra, S., Kaittanis, Ch., Nath, S., Perez, J. M. (2009). Oxidase-Like Activity of Polymer-Coated Cerium Oxide Nanoparticles. Angewandte Chemie (International ed. in English), 48(13), 2308–2312.

Salehi, Z., Zinatloo-Ajabshir , S., Salavati-Niasari, M. (2017). Dysprosium cerate nanostructures: facile synthesis, characterization, optical and photocatalytic properties. Journal of rare earths, 35(8), 805–812.

Andrievskaya, E. R., Kornienko, O. A., Sameljuk, A. V., Sayir, A. (2011). Phase Relation Studies in the CeO2-La2O3 System at 1100 to 1500 °С. Journal of the European Ceramic Society, 31(7), 1277–1283.

Andrievskaya, E. R., Kornienko, O. A., Sayir, A., Vasylkiv, O. O., Sakka, Y. (2011). Phaserelation studies in the ZrO2–CeO2–La2O3system at 1500 °С. Journal of the American Ceramic Society, 94(6), 1911–1919.

Коrnienko, О. А., Аndrievska, O. R. (2020). Phase equilibria in the Systems with ZrO2, CeO2 and Dy2O3. Innovative scientific researches: European development trends and regional aspect. Collective monograph, 4th ed, 155–179.

Grover, V., Tyagi, A. K. (2013). Ternary phase relations in CeO2–DyO1.5–ZrO2 system. Ceramics International, 39, 7563–7569.

Minkova, N., Aslanian, S. (1989). Isomorphic substitutions in the CeO2-La2O3 system at 850 C. Crystal Research and Technology, 24(4), 351–354.

Sibieude, F., Schiffmacher, G., Caro, P. (1978). Étude au microscope électronique de structures modulées dans les régions systéme La2O3-CeO2 riches en La2O3. Journal of Solid State Chemistry, 23(3-4), 361–367.

Kornienko, O., Bykov, O., Sameliuk, A., Yurchenko, Y. (2020). Phase relation studies in the CeO2-La2O3-Eu2O3 system at 1250 °С. Ukrainian Chemistry Journal, 86(3), 35–47.

Korniienko, O. A., Yushkevych, S. V., Bykov, O. I., Samelyuk, A. V., Bataiev, Yu. M., Zamula M. V. (2022). Phase equilibrium in binary La2O3-Dy2O3 and ternary CeO2-La2O3-Dy2O3 systems. Journal of the European Ceramic Society, 42(13), 5820–5830.

Schneider, J., Matsuoka, M., Takeuchi, M., Zhang, J., Horiuchi, Y., Anpo, M., Bahnemann, D. W. (2014). Understanding TiO2 Photocatalysis: Mechanisms and Materials. Chemical Reviews, 114(19), 9919–9986.

Aponte, Á. G., Ramírez, M. A L., Mora, Y. C., Marín, J. F S., Sierra, R. B. (2020). Cerium oxide nanoparticles for color removal of indigo carmine and methylene blue solutions. AIMS Materials Science, 7(4), 468–485.

Xu, Y., Deng, Ch., Dong, Ch., Wang, Q., Gao, N. (2022). Synthesis and Oxygen Storage Capability of CeO2 Powders for Enhanced Photocatalytic Degradation of Acid Orange. International Journal of Photoenergy.

Lavrynenko, O. M., Zahornyi, M. M., Pavlenko, O. Yu., Bykov, A. I. (2022). Structure and thermal behavior of CeO2 and TiO2 nanopowders doped with noble metals. Applied Nanoscience. 13, 5115–5124.

Safari-Amiri, M., Mortazavi-Derazkola, S., Salavati Niasari, M., Ghoreishi, S. M. (2017). Synthesis and characterization of Dy2O3 nanostructures: enhanced photocatalytic degradation of rhodamine B under UV irradiation. Journal of Materials Science: Materials in Electronics. 28, 6467–6474





Physical and inorganic chemistry