Structural, cohesive and electronic properties of titanium oxycarbides (TiCxO1−x) nanowires and nanotubes: DFT modeling

The atomic models for a family of the nano-sized quasi-one-dimensional titanium oxycarbides (TiCxO1−x), namely, monolithic and hollow nanomaterials-nanowires (NWs) and nanotubes (NTs) are proposed. By means of density functional theory - tight-binding (DFTB) method the structural, electronic properties, energies of formation and thermal stability for TiCxOy NWs and NTs were predicted depending on their morphology, chemical composition (in the whole range TiC-TiCxO1−x-TiO) and the presence of the atomic defects. Our results show that, monolithic TiCxOy NWs should be the most stable in the range of compositions C/O ∼ 0.2-0.6. All these TiCxOy-based nanomaterials will be metallic-like.