氟和氯在Mg（0001）表面吸附的密度泛函理论研究

摘要

The adsorption of low-coverage of F and Cl adatoms on the Mg (0001) surface was investigated using first-principles calculations based on the density functional theory (DFT). The stability of the (2 × 2) structures formed by halogen atoms adsorbed at different sites was determined. The difference between the adsorption of F and Cl on Mg (0001) surface was also discussed. The calculation results show that hollow sites are the energetically most favorable at the low-coverage. It can be concluded from the Mulliken charges and density of states that electrons transfer from the substrate Mg atoms to the adatoms, which leads to the formation of adsorbate bond and further causes the stronger interaction between Mg atom and adatom. The interaction between Cl and Mg atoms is weaker than the interaction between F and Mg.%采用基于密度泛函理论(DFT)的第一性原理研究低覆盖度F和Cl原子在Mg(0001)表面的吸附特性，分析F和Cl原子吸附在(2×2)Mg(0001)表面不同吸附位置的稳定性，讨论F和Cl原子在Mg(0001)表面的吸附。计算结果表明，在低覆盖度下，洞位是最稳定吸附位；电荷布居和态密度表明，电子从Mg原子转移至吸附原子F和Cl，从而形成吸附键，使Mg原子和吸附原子之间的相互作用增强，Cl和Mg原子之间的相互作用弱于F和Mg原子之间的相互作用。