User`s guide

Introduction to the Agilent 5500 1
Agilent 5500 SPM User’s Guide 28
between the conducting cantilever and sample, a current is generated
which is used to construct a conductivity image.
CSAFM is compatible with measurements in air, under controlled
environments, and measurements with temperature control. The
technique is useful in molecular recognition studies and can be used to
spatially resolve electronic and ionic processes across cell membranes.
It has proven useful in joint I/V spectroscopy and contact force
experiments as well as contact potential studies.
Force Modulation Microscopy (FMM)
In Force Modulation Mode (FMM), the AFM tip is scanned in contact
with the sample. As in Contact Mode, a feedback loop is used to
maintain a constant cantilever deflection, and an additional, periodic
vertical oscillation applied to the tip. The amplitude and phase of
cantilever modulation resulting from the cantilever’s interaction with
the sample varies according to the elastic properties of the sample
(Figure 9), with particular sensitivity to elasticity and viscoelasticity.
Figure 9 Cantilever response to the applied modulation changes with
surface elasticity, as well as other characteristics
NOTE
CSAFM requires a 9 ° nose cone with a pre-amp and ultra-sharp,
conducting cantilevers.
NOTE
FMM requires MAC Mode or MAC III.