Veeco Dimension 3100, Manual

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Force Imaging
Force Modulation
242 Dimension 3100 Manual Rev. D
Figure 13.6f Friction on Force Modulation Images
Tip Shape
The amount of indentation into a surface for a given applied force depends on the shape of the
cantilever tip. For the same
Drive Amplitude a sharper tip indents deeper than a dull tip. Because it
is possible for the tip to dull during imaging, replace the cantilever if the force modulation contrast
deteriorates over time. Also, note that it will be difficult to obtain reproducible, quantitative
elasticity measurements between different samples and different cantilevers because the tip shapes
may be different. In general, the force modulation technique is a qualitative tool for identifying
regions of harder and softer material on a sample, rather than a tool for quantitative analysis.
Not all samples lend themselves to standard force modulation imaging. Even samples with
excellent elasticity contrast may not show up in force modulation if their absolute elasticity is out
of instrumental range. “Negative LiftMode” may prove useful for imaging otherwise difficult
materials (see
Section 13.7.3 ).
Effect of friction on force modulation images
tip moves
down and left
substrate moves down
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