Statistical mechanics of vicinal surface : Thermodynamical interplay between adsorption and surface steps

邻接表面的统计力学：吸附和表面台阶之间的热力学相互作用

基本信息

批准号：
15540323
负责人：
AKUTSU Noriko
金额：
$ 0.96万
依托单位：
Osaka Electro-Communication University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15540323/
关键词：
step bunching adsorption statistical thermodynamics of surfaces and interfaces density matrix renormalization group formation of macro steps first-order transition at the facet edge order-disorder phase transition surface tension of crystal

项目摘要

We have presented a restricted-solid-on-solid (RSOS) model ceupled with Ising (RSOS-IC) system in order to study thermodynamical interplay between surface and adsorbate. We have made statistical mechanical calculation on the vicinal surfacu of the RSOS-IC model. by a transfer matrix method with the product wave-function renormalization group (PWFRG) algorithm, which is an extended method of the density matrix renormalization group(DMRG) algorithm.Results1.The case of the attractive interaction among adsorbates in the lateral direction.We have studied the slope, temperature, and chemical potential dependence of the surface free energy, adsorption coverage, step tension, and step stiffness. Then, we have established the thermal step bunching (or the macro step formation) in the equilibrium, where the thermal step bunching we call is the thermodynamical step condensation. We find that two mechanisms cause the thermal step bunching : the external field induced bunching, and the adsorption … More density fluctuation induced bunching.2.The case of the repulsive interaction among adsorbates in the lateral direction.In this case, the field induced thermal step bunching disappears as is expected. On the other hand, the fluctuation induced thermal step bunching appears. In low temperature, the planar surface with adsorption has adsorption induced ordered structure with √2x√2R45. In high temperature, the order is destroyed to lxldisrodered structure. Around the order-disorder transition temperature, the fluctuation of the adsorption induced ordered structure causes short-range attractive interaction between steps. Then, steps condense due to the adsorption induced inter-step attraction. By the detailed calculation, we have obtained the phase diagram.3.The case of the strong microscopic interaction between step and adsorption.The surface model with the non-monotonic temperature dependence of step stiffness has not known, so far. We find that the RSOS-IC model shown the non-monotonic temperature dependence of the step stiffness in case of the strong microscopic interaction between a step and adsorbates. Less

我们提出了一个有限的固体固体（RSOS）模型，该模型用ISING（RSOS-IC）系统引起，以研究表面和吸附物之间的热力学相互作用。我们已经在RSOS-IC模型的尾部表面进行了统计机械计算。通过使用产品波功能重新归一化组（PWFRG）算法的转移矩阵方法，这是密度矩阵重新归一化组（DMRG）algorithm.Results的扩展方法。然后，我们在等效物中建立了热步骤束（或宏步长的形成），在那里我们称之为热力学步骤缩合。我们发现两种机制导致热步骤束：外场引起的束束和吸附……更多的密度波动引起的束束。2。广告在横向方向上的排斥相互作用的情况。在这种情况下，场导致的热步骤诱导的热步骤堆积于预期的消失。另一方面，出现了波动诱导的热步束。在低温下，带有添加吸附的平面表面具有√2X√2R45的添加有序结构。在高温下，该顺序被破坏为lxldisrodred结构。围绕订单界限过渡温度，增加的有序结构的波动会导致步骤之间的短距离相互作用。然后，由于添加吸附引起的step Interpaction而导致的步骤凝结。通过详细的计算，我们获得了相图。3。步骤和吸附之间的强微观相互作用的情况。到目前为止，尚不清楚具有非单调温度依赖性的表面模型，到目前为止尚不清楚。我们发现，在台阶和吸附物之间存在强大的显微镜相互作用的情况下，RSOS-IC模型显示了步骤刚度的非单调温度依赖性。较少的