DFT Calculations Of Ti_nO(N=1-10) Clusters And Ti Surface Adsorbed An Oxygen Atom

Titanium and titanium alloys are widely used in various industries due to their low density,high strength,wear resistance and corrosion resistance.However,due to the fact that there are fewer sliding systems in ?-Ti than that in cubic crystal,the processing performance of complex titanium is poor,which hinders the development of titanium products.At the same time,titanium is very active and easily forms surface compounds with light elements including C,H,O,and N.Therefore,studying titanium and titanium oxygen clusters and oxygen adsorption on the surface of titanium can help us to understand properties of titanium materials from micro to macro evolution.With the limitations of experimental approaches,simulations have become a powerful tool for studying microscopic phenomena.In this paper,based on the framework of density functional theory(DFT),the geometry of the lowest energy state of pure Tin(n=2-11)and TinO(n=1-10)clusters,the charge distribution,as well as the geometry and charge distribution of the oxygen atom adsorbed on titanium surface are studied by using plane wave self consistent field(PWSCF).It has been found that the metallicity of pure Ti clusters will decrease when the number of cluster atoms is small.As the titanium atom increases,the cluster binding energy increases,and the structure also changes from one dimension to three dimensions.The dissociation energy of the combined system,the second-order differential energy,and the l?wdin charge population analysis show that Ti7 belongs to the magic number cluster and has special stability.Oxygen atoms tend to stay on the surface of pure Tin clusters and do not enter the interior of the clusters spontaneously,and not affect the ground state structure of the pure Ti clusters.The oxygen atom always gets electrons from the titanium atoms due to its strong nonmetality.A single oxygen atom adsorbs on the surface of titanium,and it does not enter the interior of the titanium block spontaneously.The adsorption of the oxygen atom can improve the stability of the titanium surface,and bridge adsorption of oxygen atoms is more in line with the actual adsorption situation than the other two ways.