Study of the relationship between entropy value and properties of lanthanum zirconate ceramics

In this paper, by regulating the A-site doped rare earth elements to achieve the transformation of entropy, the composition of (La1/3Nd1/3Eu1/3)2Zr2O7 (LNEZ) and (La1/4Nd1/4Eu1/4Y1/4)2Zr2O7 (LNEYZ) medium entropy ceramic system and (La1/5Nd1/5Eu1/5Y1/5Gd1/5)2Zr2O7 (LNEYGZ) high entropy ceramic system were designed and prepared. The results show that the thermal and mechanical properties of the ceramics are enhanced as the entropy value increases, and from this it is demonstrated that the crystal structure of the high-entropy LNEYGZ ceramics is the most disordered. Severe lattice distortions have the effect of hindering and enhancing the behavior of elemental expansion, phonon scattering, etc., and have the effect of enhancing the resistance of ceramics to sintering and heat insulation. Moreover, the small grain size enables the ceramic to have an enhanced ability to deflect cracks, and the fracture toughness of the ceramic is thus enhanced.