Design, Preparation and Thermal Properties of (La<sub>0.4</sub>Sm<sub>0.5</sub>Yb<sub>0.1</sub>)<sub>2</sub>Zr<sub>2</sub>O<sub>7</sub> Ceramic for Thermal Barrier Coatings

According to the theory of phonon transport and thermal expansion, a new complex rare-earth zirconate ceramic (La0.4Sm0.5Yb0.1)2Zr2O7, with low thermal conductivity and high thermal expansion coefficient, has been designed by doping proper ions at A sites. The complex rare-earth zirconate (La 0.4 Sm 0.5 Yb 0.1 ) 2 Zr 2 O 7 powder for thermal barrier coatings (TBCs) was synthesized by coprecipitation-calcination method. The phase, microstructure and thermal properties of the new material were investigated. The results revealed that single phase (La 0.4 Sm 0.5 Yb 0.1 ) 2 Zr 2 O 7 with pyrochlore structure was synthesized. The thermal conductivity and the thermal expansion coefficient of the designed complex rare-earth zirconate ceramic is about 1.3W/m•K and 10.5×10 -6 /K, respectively. These results imply that (La 0.4 Sm 0.5 Yb 0.1 ) 2 Zr 2 O 7 can be explored as the candidate material for the ceramic layer in TBCs system.