Preparation and Thermal Conductivity of Sm₂(Zr_0.6Ce_0.4)₂O₇ Ceramic

A pure Sm₂(Zr_0.6Ce_0.4)₂O₇ ceramic was prepared via solid-state reaction using ZrO₂, CeO₂, and Sm₂O₃ as the starting powders at 1600 °C for 10 h. The phase composition and microstructure were studied by X-ray diffraction (XRD), Fourier-transform infrared spectrometer (FT-IR), and scanning electron microscope (SEM). The thermal conductivity was measured by laser-flash method. The results indicated that the prepared ceramic had a pure fluorite structure. Its microstructure was dense with a relative density of 93.35% and there were no other unreacted oxides or interphases in the interfaces between grains. Because of the structure transformation from pyrochlore to fluorite, the synthesized product had a higher thermal conductivity than Sm₂Zr₂O₇ ceramic. However, the average thermal conductivity of Sm₂(Zr_0.6Ce_0.3)₂O₇ was lower than that of yttria-stabilized zirconia. The measurements of thermal conductivity suggested that the synthesized ceramic can be used as a new material for new thermal barrier coatings in the future.