Highly anti-sintering and toughened pyrochlore (Dy_0.2Nd_0.2Sm_0.2Eu_0.2Yb _0.2)₂Zr₂O₇ high-entropy ceramic for advanced thermal barrier coatings

Single-phase high-entropy rare-earth zirconate (Dy0.2Nd0.2Sm0.2Eu0.2Yb0.2)(2)Zr2O7 with excellent high-temperature phase stability at 1600 degrees C was designed and synthesized. After being heated at 1600 degrees C for 1 similar to 50 h, the average grain size of the sample increases only from 0.74 mu m to 2.22 mu m, indicating a high anti-sintering ability. The fracture toughness is 2.07 +/- 0.03 MPa m(1/2) (25 degrees C), which is 50% higher than lanthanum zirconate. The local lattice distortions induced by the atomic interactions and atomic-size mismatch are considered to be responsible for the strong anti-sintering ability and improved fracture toughness. In addition, the thermal expansion coefficient and thermal conductivity of (Dy0.2Nd0.2Sm0.2Eu0.2Yb0.2)(2)Zr2O7 are 10.59 x 10(-6) K-1 (25 similar to 1500 degrees C) and 1.14 +/- 0.09 W.m(-1).K-1 (1500 degrees C), respectively. The outstanding combination of anti-sintering ability, mechanical behavior, and thermophysical properties of (Dy0.2Nd0.2Sm0.2Eu0.2Yb0.2)(2)Zr2O7 highlights its great potential for next-generation thermal barrier coating applications.