Structural, electronic, mechanical and thermodynamic properties of antiperovskites Ti3InX (X=C and N) ceramics: A first-principles study

The mechanical and thermodynamic properties of Ti3InX (X = C and N) ceramics are investigated by the first-principles calculations. The structural and mechanical parameters are in good agreement with the available theoretical and experimental results. The results show that Ti3InX ceramics are thermodynamics stable. The stiffness and hardness of Ti3InC ceramics are higher than those of Ti3InN ceramics, but its strength is weaker than that of Ti3InN ceramics at 0K. Ti3InC and Ti3InN ceramics belong to brittle phase and ductile phase, respectively. Ti3InC and Ti3InN ceramics exhibit normal thermal expansion behavior at 0–1830K and 0–1640K, respectively, and belong to medium expansion materials and high expansion materials, respectively. The Grüneisen constants of Ti3InC and Ti3InN ceramics are 1.49–1.67 and 1.49–1.88, respectively. The thermal conductivity of Ti3InN ceramics is obviously lower than that of Ti3InC ceramics. The adsorption energy of O on Ti3InC(100) surface is lower than that on Ti3InN(100) surface, indicating that Ti3InC(100) surface is more sensitive to oxygen. Meanwhile, the melting temperature, hardness and Debye temperature of Ti3InX ceramics are also estimated.