论文标题
Au Adatom扩散在Si（100）表面的间接机制
Indirect Mechanism of Au adatom Diffusion on the Si(100) Surface
论文作者
论文摘要
Au adatom在二聚体重建的Si（100）-2x1表面的扩散的计算揭示了一种有趣的机制，该机制与位于二聚体行之间的最佳结合位点之间的直接路径显着差异。取而代之的是，主动扩散机制涉及将adatom促进到二聚体行顶部的较高能量位点，然后沿行快速迁移，访问ca。 a hundred sites at room temperature, before falling back down into an optimal binding site. This top-of-row mechanism becomes more important the lower the temperature is.计算是通过在PBESOL功能近似中从密度功能理论获得的能量表面上找到的最小能量路径进行的，然后是在200 K到900 K的一系列温度中进行扩散的动力学蒙特卡洛模拟。而直接扩散机制的激活能量为0.84 ev，在有效激活机制上，平均活化机制是平均值。
Calculations of the diffusion of a Au adatom on the dimer reconstructed Si(100)-2x1 surface reveal an interesting mechanism that differs significantly from a direct path between optimal binding sites, which are located in between dimer rows. Instead, the active diffusion mechanism involves promotion of the adatom to higher energy sites on top of a dimer row and then fast migration along the row, visiting ca. a hundred sites at room temperature, before falling back down into an optimal binding site. This top-of-row mechanism becomes more important the lower the temperature is. The calculations are carried out by finding minimum energy paths on the energy surface obtained from density functional theory within the PBEsol functional approximation followed by kinetic Monte Carlo simulations of the diffusion over a range of temperature from 200 K to 900 K. While the activation energy for the direct diffusion mechanism is calculated to be 0.84 eV, the effective activation energy for the indirect mechanism is on average 0.56 eV.
