Instruction manual

Lateral Force Mode
Advanced LFM Operation
Rev. B MultiMode SPM Instruction Manual 173/(174 Blank)
10.2.7 Height Artifacts in the Signal
LFM is subject to height artifacts due to coupling with surface topography. Delay in the feedback
loop causes the tip to momentarily twist as it climbs up an edge. This will be visible in the friction
data if it’s severe enough.
To distinguish real friction data from height artifacts, remember that friction causes the cantilever to
twist in the opposite direction as it travels. Actual LFM information will always show up as a mirror
image in the trace and retrace directions in the scope display. Height artifacts will be the same
direction in the scope display (see Figure 10.2e).
Figure 10.2e Height Artifacts in LFM Data
Trace
Retrace
High Friction
High Friction
Low Friction