Veeco Dimension 3100, Manual

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Electric Techniques
Electric Force Microscopy
Rev. D Dimension 3100 Manual 291
16.2.4 Phase Detection
Phase Detection is only available when the Extender Electronics Module has been correctly
configured into the system.
1. In the Auto Tune Controls window, set Start frequency and End frequency to appropriate
values for your cantilever (e.g., for 225µm MFM cantilevers, set Start frequency to 40kHz
and End frequency to 100 kHz).
2. Select Auto Tune .
Note: Two curves appear on the Cantilever Tune graph (see Figure 16.2o ): the
amplitude curve in white (the solid line in Figure 16.2o ), and the phase curve in
yellow (the dashed line).
Figure 16.2o Phase Detection Cantilever Tune
(Extender Electronics Module Installed)
Note: The phase should decrease with increasing frequency and cross the center line
(0° point) at the peak frequency. The phase curve then correctly reflects the
phase lag between the drive and the cantilever response. Gradients in the
electric force cause a shift
∆
F
0
in the resonance frequency. Resonance shifts
also give rise to phase shifts
∆φ
used to generate an image of the electric force
gradients; see Figure 16.2p .
Figure 16.2p Shift In Phase at Fixed Drive Frequency
Frequency Sweep
∆φ
Drive Frequency
90
0
180
Phase (deg)
∆
F
0