Deformation Modes and Anisotropy of Anti-Perovskite Ti(3)AN (A = Al, In and Tl) from First-Principle Calculations

Deformation modes were studied for Ti(3)AN (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 Ti(3)AN were investigated using the pseudo potential plane-wave method based on density functional theory. We found that the anisotropy of Ti(3)InN was significantly larger than that of Ti(3)AlN and Ti(3)TlN. 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 Ti(3)InN is a good thermal barrier material.