Abstract
La2(Zr0.7Ce0.3)2O7(LZ7C3) ceramic was prepared by solid state reaction method at 1400 °C for 12h using La2O3, ZrO2, and CeO2 as starting reactants. The phase composition and microstructures were studied by XRD and SEM technology. The thermal conductivity and linear thermal expansion coefficient were investigated by laser-flash method and pushing-rod method respectively. XRD results revealed that LZ7C3 is a mixture of pyrochlore and fluorite, and the pyrochlore is the main phase which is a small solid solution of La2Ce2O7 (LC) in La2Zr2O7 (LZ). The thermal conductivity of LZ7C3 decrease gradually with the increase in temperature until 1200°C, and the value is 0.79 W⋅m-1⋅K-1, which is almost 50% lower than that of LZ. The linear thermal expansion coefficient which is 11.6 × 10-6 K-1 at 1200°C is larger than that of LZ. These results show that LZ7C3 ceramic material can be explored as a novel prospective candidate material for use in new thermal barrier coating systems in the future.