掺Cr,Ni对S在Fe(100)面吸附的第一性原理研究

基于密度泛函理论(DFT)的第一性原理方法,在广义梯度近似下计算了Fe中掺Cr或Ni时S原子在Fe(100)面吸附的结构和电子性质,并计算了其分子轨道和吸附能。结果表明:S原子均是吸附在H位最稳定;纯铁时S在Fe(100)面H位的吸附能为-7.70 eV,掺Ni时S原子在H位的吸附能为-7.35 eV,吸附能的相对变化为4.5%;掺Cr时S原子在H位的吸附能为-5.79 eV,吸附能相对纯铁时变化为24.8%,表明掺Cr对S原子在Fe表面的吸附抑制作用更大。对比分析了每种吸附情况下的分波态密度,结果发现掺Cr时具有较高的局域电子云重叠,从而产生的排斥作用抑制了S原子的吸附。

First Principle Study of Doped Cr and Ni for the Adsorption of S on Fe (100)

The adsorption of a sulfur atom on the Fe(100) surface for Cr or Ni impurities in Fe was studied with the first principle method based on the density functional theory(DFT).The structures,electronic properties,molecular orbital and adsorption energies were calculated with the generalized gradient approximation.The results show that S adsorbed on H site is most stable.The adsorption energy in H site for pure Fe is -7.70 eV,for Ni impurities in Fe is-7.35 eV and for Cr is-5.79 eV.The relative change of the adsorption energy is 4.5% for Ni impurities in Fe,and for Cr is 24.8%.The discussion above indicates that Cr impurities in Fe produce stronger inhibition for the adsorption of sulfur.The partial density of states(PDOS) for different adsorption cases were analyzed.The result shows that the overlap of higher local electron cloud for Cr impurities in Fe produces the repulsion and inhibition for the adsorption of sulfur.