WANG Tijue ¹, ZHANG Jinhua ¹, KE Changming ¹, WU Hongdan ², YU Jishun ³, WANG Jingran ¹
(1. The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, Hubei,
China; 2. Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgy Mineral Resources, Wuhan University of
Science and Technology, Wuhan 430081, Hubei, China; 3. State Key Laboratory of Geological Process and Mineral Resources, China
University of Geosciences, Wuhan 430074, Hubei, China)

Abstract: 0.5xSm₂O₃-(1-x)CeO₂ (x = 0-1.0) powders were prepared by reverse coprecipitation-calcination method and characterized by X-ray diffraction. The crystal structure of powders changed from single fluorite structure to the combination of fluorite and C-type cubic structure,then to trigonal structure, with the increase of x-value. An empirical equation simulating the lattice parameter of samarium doped ceria was established based on the experimental data. The lattice thermal expansion behavior of solid solutions with fluorite structure was investigated by the high temperature in-situ X-ray diffraction. The lattice parameters of the solid solutions increased linearly with Sm³⁺ content and heating temperatures increasing. The average thermal expansion coefficients of samarium doped ceria with fluorite structure were higher than 12.5×10^-6 ℃-1 at room temperature to 1200 ℃.

Key words: samarium-doped ceria; crystal structure; lattice thermal expansion.