Structural, elastic, thermal and mechanical properties of LnTa2O6(Ln Ce-Tb) ceramics from first-principles calculations

Thermal barrier coatings (TBCs) are essential materials in many fields for protecting high temperature components. In this work, first-principles calculations are performed to explore the thermal-mechanical properties of LnTa2O6 (LnCe-Tb) ceramics. The formation energy and Born stability criteria confirm that LnTa2O6 is structural stable. LnTa2O6 exhibits superior fracture toughness (1.712–1.817 MPa·m1/2) and thermal conductivity (1.032–1.073 W/m∙K) than many typical tantalate candidates. Besides, LnTa2O6 ceramics present lower Young’s modulus (195.5–210 GPa) and comparable hardness (10.268–10.953 GPa) than those of YSZ. LnTa2O6 ceramics with high melting temperatures of 2000 K are promising for next generation turbine engines.