Effect of CaO and CeO2 co-doping on thermo-physical properties of La2Z2O7

Abstract

Ce4+ and Ca2+ modified La2Zr2O7 samples, La2Zr2O7, (La0.8Ce0.2)2(Zr0.7Ce0.3)2O7.2 and (La0.6Ce0.2Ca0.2)2(Zr0.7Ce0.3)2O7, were prepared by the co-precipitation method to obtain enhanced thermos-physical properties. Compared with La2Zr2O7, (La0.8Ce0.2)2(Zr0.7Ce0.3)2O7.2 and (La0.6Ce0.2Ca0.2)2(Zr0.7Ce0.3)2O7 both exhibited better sintering resistance, lower thermal conductivities, and higher thermal expansion coefficients. The underlying mechanism of the improved thermo-physical performance of La2Zr2O7 induced by Ce4+ and Ca2+ doping was discussed. The thermal conductivity and thermal expansion coefficient of (La0.6Ce0.2Ca0.2)2(Zr0.7Ce0.3)2O7 were 1.165 W·m−1·K−1 at 1450°C and 10.91 × 10−6 K−1, respectively, making it a promising material for the thermal barrier coatings (TBCs).

Keywords

• e: thermal applications
• c: thermal expansion
• c: thermal conductivity