Atomic scale wear of layred crystal structure material by atomic force microscope

同时观察了白云母的原子尺度地形图和原子尺度横向力显微镜（LFM）图像。然后，从滑动引起的侧向力和表面原子形貌变化两方面评价了原子磨损现象。在约100 nN的载荷下，在无损伤的云母表面形成凹槽。在云母表面约1nm深度的磨损，对应于从一个解理面表面到紧挨着它的解理面表面的深度。利用这一磨损机理，利用原子力显微镜对白云母等层状晶体结构材料进行了原子尺度的机械加工。加工开始于某一临界载荷，加工深度随载荷离散增加。在SiO_4-K和K-SiO_4界面的两个解理面上易发生断裂。评估了加工深度对载荷的依赖关系。磨损槽的深度随载荷的增加而增加。将尖梁扭转得到的加工侧向力分为犁力和摩擦力。犁耕力与加工深度成正比。尖端的几次机械滑动循环通过从表面去除钾而产生了1纳米深的凹槽，这与SiO_4的上表面到其下一层SiO_4的上表面的距离相对应。采用逐级机械滑动法加工深度为1 nm的四阶沟槽。观察了与SiO_4基面相对应的坡面各阶面的原子图像。然后用机械尖端滑动法加工字母NIT（刻度为2000X600X1nm）。

Atomic-scale topographic images and atomic-scale lateral force microscope (LFM) images of muscovite mica were observed simultaneously. Then, the atomic wear phenomenon was evaluated from lateral force and surface atomic topographic changes caused by sliding. Above about 100 nN load, grooves were formed on the damage-free mica surface. Wear about one nm deep in the mica surface corresponds to the depth from the surface of one cleavage plane to the surface of the cleavage plane immediately beneath it. By applying this wear mechanism atomic-scale mechanical processing of layred crystal structure materials such as muscovite mica was performed using an atomic force microscope (AFM). Processing began at a certain critical load, and the processing depth increased discretely with load. Fracture easily occurred at the two cleavage planes of SiO_4-K and K-SiO_4 interfaces. The processing depth dependence on load was evaluated. The depth of the wear grooves increased with load. Processing lateral force estimated from the torsion of the tip beam was divided into plowing force and friction force. The plowing force is proportional to processed depth. Several cycles of mechanical sliding of the tip generated a 1-nm-deep groove by removing potassium from the surfaces which corresponded to the distance from the top surface of SiO_4 to the top surface of the next SiO_4 layr beneath it. A groove with four steps of one-nm depth was processed by stepwise mechanical sliding. Atomic images of each step surface of the groove corresponding to the SiO_4 basal plane were observed. Then the letters NIT (scale 2000X600X1nm) was procesed by mechanical tip sliding.