【作者】 李登峰； 肖海燕； 祖小涛； 董会宁；

【Author】 LI Deng-feng~(1,2) XIAO Hai-yan~1 ZU Xiao-tao~1 DONG Hui-ning~2 (1.Department of Applied Physics,University of Electronic Science and Technology of China,Chengdu 610054,China;2.Institute of Applied Physics and College of Electronic Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China)

【机构】 电子科技大学物理电子学院应用物理系； 重庆邮电大学光电工程学院应用物理研究所；

【摘要】 用第一性原理的自旋密度泛函理论计算了 Sn 和 Pb 吸附在 Ni（111）(（3）^1/2×（3）^1/2)R30°表面的几何构型和功函变化．能量计算表明 Sn 和 Pb 吸附在 Ni（111）(（3）^1/2×（3）^1/2)R30°表面形成的最稳定相均是替代吸附,并不存在类似于 Sb 吸附于 Cu（111）(（3）^1/2×（3）^1/2)R30°和 Ag（111）(（3）^1/2×（3）^1/2)R30°表面时形成的层错现象,验证了以前的实验结果．对于 Sn 和 Pb 吸附在 Ni（111）(（3）^1/2×（3）^1/2)R30°表面形成的最稳定表面合金相,表面弛豫效应都不明显,皱褶幅度分别为0．0548和0．0987nm,都比硬球模型所预言的小,表明 Sn-Ni 和 Pb-Ni 金属键含有大量的共价键成分．计算所得的几何参数与实验符合得很好．Sn 和 Pb 在 Ni（111）(（3）^1/2×（3）^1/2)R30°表面吸附前后的功函变化值分别为 0．38和0．433eV,表示电荷均从底物移向吸附物．更多还原

【Abstract】 The geometry property and work-function change of Sn and Pb adsorption on Ni（111）(3^1/2×3^1/2)R30° surface were investigated by using the density functional theory method of first-principles.Total energy calculations show that substitutional surface alloy phases in the outermost layer are preferable for Sn and Pb adsorption on Ni（111）(3^1/2×3^1/2)R30° surface,and they have no stacking fault like that found for similar phases of Sb on Cu（111） and Ag（lll）.It confirmed the earlier experiments.In the case of the most stable surface alloy phases for Sn and Pb adsorption on Ni（111）(3^1/2×3^1/2)R30° surface,the relaxation effects are marginal and the rumpling magnitudes are 0.0548 and 0.0987nm,respectively.They are smaller than the predictions from hard-sphere model, indicating of the covalent character in the bonds of Sn-Ni and Pb-Ni.Main su’uctural parameters from experimental results are reproduced by our calculations.The changes of work-function due to Sn and Pb adsorption were found to be 0.38 and 0.43 eV for the Ni（111）(3^1/2×3^1/2) R30° surface,respectively.It shows that the charge is transformed from the substrate to the adsorbates.更多还原