Thermophysical properties of Sm_2(Zr_(1-x)Ce_x)_2O_7 ceramics

摘要

Sm2(Zr1-xCex)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 Sm2(Zr0.9Ce0.1)2O7 with pyrochlore structure and Sm2(Zr1-xCex)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(Zr0.8Ce0.2)2O7 and Sm2(Zr0.7Ce0.3)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.