Thermophysical properties of Sm₂(Zr_1-x Ce _x )₂O₇ ceramics

Sm₂(Zr_1-x Ce _x )₂O₇ (x = 0.1, 0.2, and 0.3) ceramics were prepared by solid reaction method at 1600°C for 10 h using Sm₂O₃, ZrO₂, and CeO₂ as starting reactants. The phase compositions, microstructures, thermal expansion coefficients, and partial thermal conductivities of these materials were investigated. X-ray diffraction (XRD) results reveal that Sm ₂(Zr_0.9Ce_0.1)₂O₇ with pyrochlore structure and Sm₂(Zr_1-x Ce _x ) ₂O₇ (x = 0.2 and 0.3) with fluorite structure were synthesized, and scanning electrical microscopy (SEM) images show that the microstructures of these products are very dense. The linear thermal expansion coefficients increase with increasing temperature in the temperature range from ambient to 1200°C, and the thermal expansion coefficients increase with increasing content of doped CeO₂. The thermal conductivities of Sm₂(Zr_0.8Ce_0.2)₂O₇ and Sm₂(Zr_0.7Ce_0.3)₂O₇ decrease gradually with an increase in temperature. These results show that the synthesized ceramic materials can be explored as novel prospective candidate materials for use in new thermal barrier coating systems in the future.