Kocán Pavel, Sobotík Pavel, Ošt'ádal Ivan
Charles University in Prague, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holešovičkách 2, 180 00 Prague 8, Czech Republic.
Phys Rev E Stat Nonlin Soft Matter Phys. 2013 Aug;88(2):022403. doi: 10.1103/PhysRevE.88.022403. Epub 2013 Aug 14.
We used a configuration-based kinetic Monte Carlo model to explain important features related to formation of the (√3×√3)R30° mosaic of metal and semiconductor atoms on the Si(111) surface. Using first-order desorption processes, we simulate the surprising zero-order desorption spectra, reported in some cases of metal desorption from the Si(111) surface. We show that the mechanism responsible for the zerolike order of desorption is the enhanced desorption from disordered areas. Formation of the √3×√3 mosaic with properties of a strongly frustrated antiferromagnetic Ising model is simulated by a configuration-sensitive desorption. For substitution of desorbed metal atoms by Si adatoms, fast diffusion of the adatoms on top of a 1×1 layer is proposed as the most probable. Simulations of desorption-induced structural transitions provide us a link between underlying atomistic processes and the observed evolving morphologies with resultant macroscopic desorption fluxes. An effect of the desorption sensitivity on a configuration of neighboring atoms is emphasized.
我们使用基于构型的动力学蒙特卡罗模型来解释与Si(111)表面上金属和半导体原子的(√3×√3)R30°镶嵌体形成相关的重要特征。利用一级脱附过程，我们模拟了在某些从Si(111)表面脱附金属的情况下所报道的令人惊讶的零级脱附光谱。我们表明，导致脱附呈现类零级的机制是无序区域脱附增强。通过构型敏感脱附模拟了具有强阻挫反铁磁伊辛模型性质的√3×√3镶嵌体的形成。对于用Si吸附原子取代脱附的金属原子，最有可能的是吸附原子在1×1层顶部的快速扩散。脱附诱导的结构转变模拟为我们提供了潜在原子过程与观察到的演化形态以及由此产生的宏观脱附通量之间的联系。强调了脱附敏感性对相邻原子构型的影响。
