First-principles calculations of metal surfaces.Ⅱ. Properties of low-index platinum surfaces toward understanding electron emission

摘要

The stability of low-index platinum surfaces and their electronic properties is investigated with density functional theory,toward the goal of understanding the surface structure and electron emission,and identifying precursors to electrical breakdown,on nonideal platinum surfaces.Propensity for electron emission can be related to a local work function,which,in turn,is intimately dependent on the local surface structure.The (1×N) missing row reconstruction of the Pt( 110) surface is systematically examined.The (1 × 3) missing row reconstruction is found to be the lowest in energy,with the (1×2) and (1×4) slightly less stable.In the limit of large (1×N) with wider (111) nanoterraces,the energy accurately approaches the asymptotic limit of the infinite Pt( 111) surface.This suggests a local energetic stability of narrow (111) nanoterraces on free Pt surfaces that could be a common structural feature in the complex surface morphologies,leading to work functions consistent with those on thermally grown Pt substrates.