Structure, stability, and electronic properties of thin TiO2 nanowires

We present a comprehensive theoretical study-within the framework of an ab initio density-functional-theory method-of the structural, stability, and electronic properties of thin TiO2 nanowires. We consider nanowires with << 001 >> growth direction with several perimeters and surface-facet configurations. We use a stability analysis of the results obtained for these nanowires to determine the most stable geometries. Our results show that nanowire with the square cross section is the least stable among the octagonal, hexagonal, and round shape nanowires studied. We show that the perimeter of the nanowires is an important dimensional parameter when considering stability and that the surface facets play a central role on the energetics and stability of the nanowires.