Atomic Force Microscopy adds a whole new dimension to your laboratory capability. AFM gives you more than SEM's 2-D images of a surface - AFM provides true 3-D topographic images which also yield surface roughness data on the nano-meter scale. Consequently, AFM is ideal for characterizing metal coatings and finished surfaces, and can provide surface roughness data that is similar to that of a profilometer. In addition to providing topographic data, AFM can also reveal information such as the relative frictional properties of heterogeneous phases.

       The two images of a Zn electrode below illustrate the large range of areas and resolutions that can be examined with AFM, from tens of microns to the nanometer scale.

       When a typical commercial razor blade is used for cutting, a teflon coating on the stainless steel blade continually erodes until a thin residual layer is all that remains. The continuity of this layer is difficult to resolve from the steel in topography images, and is almost impossible to image otherwise; yet, with the use of lateral force mode, the frictional behavior of the teflon stands out strongly from the metallic substrate, revealing the degree of dispersion of the teflon. In this case, brighter metallic regions are "stickier" than the teflon in Lateral Force Mode. This is intuitively correct, since teflon is often called a "non-stick" material.

       The AFM topography images below were taken from corroded sheet metal. The image at left was taken outside the corrosion halo and shows a polishing texture that is typical of finished metals. The corrosion halo at right has a strikingly different surface texture relative to the virgin surface, yet its surface roughness does not differ from the polishing texture. An SEM analysis reveals little in this study because it cannot adequately resolve these surface textures in the z-direction, and neither can SEM give us meaningful z-roughness data.