(La0.2Y0.2Nd0.2Gd0.2Sr0.2)CrO3: A novel conductive porous high-entropy ceramic synthesized by the sol-gel method

Highlights: • The chromate rare earth-based high-entropy ceramic powder was prepared by the sol-gel method. • The electrical conductivity of high-entropy ceramic at room temperature was approximately 6.6743 Ω·cm when the porosity was 38.90%. • By increasing the porosity, the effect of pore defects on resistivity and thermal conductivity was studied. -- Abstract: A single-phase homogeneous (La_0.2Y_0.2Nd_0.2Gd_0.2Sr_0.2)CrO₃ powder with high configurational entropy was synthesized by using the sol-gel method. The powder was obtained under mild experimental conditions, the crystal grains were fine and uniform, and the elements were evenly dispersed. We sintered the powders into monolithic porous green body by adding cellulose nanocrystals, which had good electrical conductivity. Their electrical conductivity at room temperature was approximately 6.6743 Ω·cm when the porosity was 38.90%. The experimental results showed that as the porosity increased, the resistivity increased and the thermal conductivity decreased accordingly. This trend occurred because of an increase in the porosity and a decrease in the connection of the particles; thus, the electron hole carriers were subjected to a greater resistance when passing through the junction. The combination of these properties indicates that the porous high-entropy (La_0.2Y_0.2Nd_0.2Gd_0.2Sr_0.2)CrO₃ ceramic possesses promise in the field of high-temperature electrochemical materials.