Porous (Ce0.2Zr0.2Ti0.2Sn0.2Ca0.2)O2-δ high-entropy ceramics with both high strength and low thermal conductivity

Single-phase (Ce 0.2 Zr 0.2 Ti 0.2 Sn 0.2 Ca 0.2 )O 2-δ porous high-entropy ceramics have been in-situ fabricated by foam-gelcasting-freeze drying method at different temperatures. The microstructure, phase composition, and properties of the obtained ceramics were investigated. The results indicate that compared with other porous ceramics reported in the literatures, this type of ceramics exhibits excellent performance. The sample prepared at 1350 °C shows high porosity (88.6 %), low thermal conductivity (0.023 W m -1  K -1 ), and high compressive strength (1.48 MPa). The current study suggests that porous (Ce 0.2 Zr 0.2 Ti 0.2 Sn 0.2 Ca 0.2 )O 2-δ high entropy ceramics are promising candidates for thermal insulation applications.