Deformation Modes and Anisotropy of Anti-Perovskite Ti₃AN (A = Al, In and Tl) from First-Principle Calculations

Deformation modes were studied for Ti₃AN (A = Al, In and Tl) by applying strain to the materials using first-principle calculations. The states of the bonds changed during the deformation process, and the Ti-N bonds remained structurally stable under deformation. The elastic anisotropy, electronic structures, hardness, and minimum thermal conductivity of anti-perovskite Ti₃AN were investigated using the pseudo potential plane-wave method based on density functional theory. We found that the anisotropy of Ti₃InN was significantly larger than that of Ti₃AlN and Ti₃TlN. All three compounds were mechanically stable. The band structures of the three compounds revealed that they were conductors. The minimum thermal conductivities at high temperature in the propagation directions of [100], [110], and [111] were calculated by the acoustic wave velocity, which indicated that the thermal conductivity was also anisotropic. It is indicated that Ti₃InN is a good thermal barrier material.