La2Zr2O7 based high entropy ceramic with a low thermal conductivity and enhanced CMAS corrosion resistance

Herein, five new La2Zr2O7 based high-entropy ceramic materials, such as (La0.2Ce0.2Gd0.2Y0.2Er0.2)2Zr2O7, (La0.2Ce0.2Gd0.2Er0.2Sm0.2)2Zr2O7, (La0.2Gd0.2Y0.2Er0.2Sm0.2)2Zr2O7, (La0.2Ce0.2Y0.2Er0.2Sm0.2)2Zr2O7, (La0.2Ce0.2Gd0.2Y0.2Sm0.2)2Zr2O7), were synthesized using a sol-gel and high-temperature sintering (1000 °C) method. The spark plasma sintered (SPS) (La0.2Ce0.2Gd0.2Er0.2Sm0.2)2Zr2O7 pellet shows a low thermal conductivity of 1.33 W m-1 K-1 at 773 K, and it also exhibits better CaO–MgO–Al2O3–SiO2 corrosion resistance than that of Y2O3 stabilized ZrO2. It shows that (La0.2Ce0.2Gd0.2Er0.2Sm0.2)2Zr2O7 has a promising application potential as a thermal barrier coating.