Study on the Surface Structure and Surface Energy of Rutile TiO2 (110) by Molecular Dynamics

摘要

The TiO2 layer on Ti-materials surface influences strongly on biological response, thus it is significant to study on the surface structure and surface energy. We study systematically on the relaxed structures of the rutile TiO2 (110) by molecular dynamics (MD) simulation, correct the formula for surface energy according to the slab models of MD simulation, and calculate the surface energy of the slab model containing 2 to 16 Ti-O layers. We find that the surface atomic displacements reach certain values at the slab models at least 6 Ti-O layers, and govern the surface energy. Moreover the surface energy is a function of the slab thickness (number of Ti-O layers), which converges to 1.05 Jm-2, and the difference of surface energy among slab models containing more than 12 layers is less than 0.02Jm-2. The surface energy of the large-scale rutile (110) surface by MD simulation is in agreement with one by first-principles calculations. And the correction formula for surface energy is aid to evaluate the large-scale complex structures by MD.