Modeling atomic force microscopy at LiNbO3 surfaces from first-principles
Modeling atomic force microscopy at LiNbO3 surfaces from first-principles
复制标题
DOI：
10.1016/j.commatsci.2015.03.025
复制
发表时间：
2015-06
影响因子：
3.3
通讯作者：
S. Sanna;C. Dues;W. Schmidt
中科院分区：
文献类型：
--
作者：
S. Sanna;C. Dues;W. Schmidt
从第一性原理出发，模拟了LiNbO 3表面的原子力显微镜（AFM）。利用密度泛函理论计算了不同原子尖模型与x切和z切LiNbO 3表面相互作用时所受的力。原子分辨AFM测量的AFM模拟进行了比较。在模拟中发现的物种依赖的尖端-表面相互作用允许用于不同表面的微观模型的验证。特别是，它示出的原子力显微镜的对比度是由在氧离子的电荷积累。货车德瓦耳斯力使扫描变得模糊，而没有定性地改变AFM图案。这里提出的微观表面模型解释了测量的AFM图案的起源和观察到的空间分辨率差异对应于不同的表面取向。
Atomic force microscopy (AFM) at LiNbO3surfaces is simulated from first-principles. The forces acting on different atomic tip models interacting withx-cut andz-cut LiNbO3surfaces are calculated within density functional theory. The AFM simulations are compared with atomic resolved AFM measurements. The species-dependent tip-surface interaction found in the simulation allows for the verification of microscopic models for different surfaces. In particular, it is shown that the atomic force microscopy contrast is governed by the charge accumulation at the oxygen ions. Van der Waals forces cloud the scans, without qualitatively modifying the AFM pattern. The microscopic surface models proposed here explain both the origin of the measured AFM patterns and the observed spatial resolution difference corresponding to different surface orientations.