Influence of size disorder parameter on the thermophysical properties of rare-earth-zirconate medium-entropy ceramics

Inspired by the concept of entropy stabilization, a series of rare-earth-zirconate medium-entropy ceramics were designed. The influence of size disorder parameter on the mechanical and thermophysical properties of rare-earth-zirconate medium-entropy ceramics was investigated. The results show that the prepared rare-earth-zirconate medium-entropy ceramics exhibit single pyrochlore structure, and the lattice constant is linearly related to the average doped rare-earth ionic radius. The scanning electron microscope-energy-dispersive spectroscopy results indicate the uniform distribution of doped rare-earth elements. The rare-earth-zirconate medium-entropy ceramics have relative density above 98.1% with high mechanical properties (H-V similar to 10.0 GPa, K-I similar to 2.50 MPa m(0.5), and E-0 similar to 220 GPa). (La1/3Eu1/3Gd1/3)(2)Zr2O7 medium-entropy ceramics with a larger delta size${\delta }_{size}$ (4.36%) present relatively high thermal expansion coefficients (10.93 x310(-6) K-1, 1200 degrees C) and low thermal conductivity (1.57-1.58 W/(m K), 100-500 degrees C). These results suggest that the prepared rare-earth-zirconate medium-entropy ceramics can be used as a new type of thermal insulation materials.

Automated summary

Inspired by entropy stabilization, a series of rare-earth-zirconate medium-entropy ceramics were designed and their mechanical and thermophysical properties were investigated. The results show that these ceramics have good mechanical properties and low thermal conductivity, making them suitable for thermal insulation applications.