原子力显微镜Force Volumn功能介绍

Any small particle that approaches a surface experiences a number of forces before and after contact with the surface. Using an atomic force microscope (AFM) tip, or a small particle attached to an AFM cantilever, the AFM can be used to probe these forces between the tip (or particle of your choice) and a surface. This is done by recording the cantilever deflection as the tip approaches, contacts, and retracts from a surface, then plotting a force curve as a function of the approach-retract travel distance. These types of force measurements can contain information about the electrostatic, chemical, and magnetic properties of surfaces and materials. Because most surfaces being examined are not homogeneous, it is often of interest to collect an array of force curves. Such an array produces information about the lateral distribution of different surface and/or material properties. For example, using a charged tip to probe a surface with patches of charge allows one to localize and characterize the patches on the surface. Previously, obtaining distributions of force curves over an area required manual setting of the x and y offset parameters to each new position in the array. This was tedious and resulted in sparse force sampling of the area. Now collecting this array of data is highly automated on Veeco Instruments AFMs and is referred to as “Force Volume Imaging”.