Preparation and thermophysical properties of (Sm1−xErx)2Ce2O7 oxides for thermal barrier coatings

(Sm1−xErx)2Ce2O7 ceramics were synthesized by sol–gel method and sintered at 1600 °C for 10 h in air. The influence of Er2O3-substitution on the phase structure and thermophysical properties of Sm2Ce2O7 was investigated. The phase structures of these ceramics were identified by X-ray diffraction showing that all synthesized ceramics have fluorite-type structure. The measurements for thermophysical properties of these ceramics show that their thermal conductivities and thermal expansion coefficients remarkably decreased through Er-substitution. However, the thermal expansion coefficients were higher than that of YSZ and their thermal conductivities were much lower than that of 8YSZ. The excellent thermophysical property implies that these solid solutions are potential materials for the ceramics layer in thermal barrier coatings.