Preparation and thermophysical properties of (La_0.4Sm _0.5Yb_0.1)₂(Zr_0.7Ce _0.3)₂O₇ ceramic for thermal barrier coatings

A complex rare-earth zirconate (La_0.4Sm_0.5Yb _0.1)₂(Zr_0.7Ce_0.3)₂O ₇ powder for thermal barrier coatings (TBCs) was synthesized by coprecipitation method. The phase composition, microstructure and the thermophysical properties were investigated. XRD results revealed that single phase (La_0.4Sm_0.5Yb_0.1)₂(Zr _0.7Ce_0.3)₂O₇ with pyrochlore structure was prepared and the SEM result showed that the microstructure of the product was dense and no other phases existed among the particles. With the temperature increasing, the thermal expansion coefficient (CTE) of the ceramic increased, while the thermal conductivity decreased. The results indicated that CTE of the ceramic was slightly higher than that of La₂Zr ₂O₇ and the thermal conductivity of the ceramic was lower than that of La₂Zr₂O₇. These results imply that (La_0.4Sm_0.5Yb_0.1)₂(Zr _0.7Ce_0.3)₂O₇ can be explored as the candidate material for the ceramic layer in TBCs system.