Oxygen adsorption on Nb(110) surface by first-principles calculation
氧在Nb(110)表面吸附的第一性原理研究

The adsorption of atomic oxygen on the Nb(110) surface is systematically investigated through the first-principles method for oxygen coverage ranging from 0.25 to 1 monolayer(ML).It is found that the hollow site is the most energetically favorable for the whole coverage range considered and that the long-bridge site takes the second place.The work function increases almost linearly with the increase of oxygen coverage for the long-bridge site adsorption,whereas for the hollow site adsorption the work function decreases when the coverage is 0.25 ML or 0.5 ML and increases when the coverage is 0.75 ML or 1 ML.Using the planar averaged charge density and the dipole moment change we can explain the complicated change of work function induced by atomic oxygen adsorption.In addition,the interaction between O and Nb is analyzed by the surface atomic structure and electronic density of states.