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采用第一性原理的密度泛函方法对过渡金属碳化物MC(111)清洁表面构型和电子结构进行系统研究.结果表明,与理想表面相比,表面弛豫导致表层金属原子和次表层碳原子分别朝体相和真空方向位移,从而导致层间距的收缩.由能带计算结果得知,紧邻或被EF穿越的活性表面态成分均为表面金属原子的dxz/dyz轨道.进一步考察了弛豫对表面态组成的影响,并对表面芯能级位移和功函进行了探讨.
The first-principle density-functional method was used to systematically study the clean surface configuration and electronic structure of the transition metal carbide MC (111). The results show that surface relaxation leads to surface metal atoms and subsurface carbon The atoms move towards the bulk and the vacuum, respectively, resulting in the shrinkage of the layer spacing. From the band calculation results, the active surface state components that are adjacent to or crossed by EF are the dxz / dyz orbital of the surface metal atom. Yu on the surface state of the composition of the surface core energy level displacement and work function were discussed.