Baykara Mehmet Z, Schwendemann Todd C, Albers Boris J, Pilet Nicolas, Mönig Harry, Altman Eric I, Schwarz Udo D
Department of Mechanical Engineering and Materials Science and Center for Research on Interface Structures and Phenomena (CRISP), Yale University, PO Box 208284, New Haven, CT 06520, USA.
Nanotechnology. 2012 Oct 12;23(40):405703. doi: 10.1088/0957-4484/23/40/405703. Epub 2012 Sep 20.
A non-contact atomic force microscopy-based method has been used to map the static lateral forces exerted on an atomically sharp Pt/Ir probe tip by a graphite surface. With measurements carried out at low temperatures and in the attractive regime, where the atomic sharpness of the tip can be maintained over extended time periods, the method allows the quantification and directional analysis of lateral forces with piconewton and picometer resolution as a function of both the in-plane tip position and the vertical tip-sample distance, without limitations due to a finite contact area or to stick-slip-related sudden jumps of tip apex atoms. After reviewing the measurement principle, the data obtained in this case study are utilized to illustrate the unique insight that the method offers. In particular, the local lateral forces that are expected to determine frictional resistance in the attractive regime are found to depend linearly on the normal force for small tip-sample distances.
一种基于非接触原子力显微镜的方法已被用于绘制石墨表面对原子级尖锐的铂/铱探针尖端施加的静态横向力。在低温和吸引区域进行测量时，由于在此期间尖端的原子锐度可以长时间保持，该方法能够以皮牛顿和皮米分辨率对横向力进行量化和方向分析，这是作为平面内尖端位置和垂直尖端 - 样品距离的函数，不受有限接触面积或尖端顶点原子与粘滑相关的突然跳跃的限制。在回顾测量原理之后，利用本案例研究中获得的数据来说明该方法所提供的独特见解。特别是，发现在小尖端 - 样品距离下，预期会决定吸引区域中摩擦阻力的局部横向力与法向力呈线性关系。
