User`s guide

Introduction to the Agilent 5500 1
Agilent 5500 SPM User’s Guide 29
Lateral Force Microscopy (LFM)
Lateral Force Microscopy (LFM) is a derivative of Contact AFM with
the scan direction perpendicular to the long axis of the cantilever. In
LFM, the tip is constantly in contact with the sample surface. In addition
to its vertical deflection, the cantilever also twists in the scan direction.
As a result, along with the near-vertical deflection signal which is
usually present during Contact Mode AFM, the detector can also collect
a sizeable lateral defection (Friction) signal from the cantilever‘s
twisting motion. The strength of the lateral deflection signal is related to
the friction force between the sample surface and the tip; thus, LFM is
sometimes called Friction Force Microscopy.
The LFM signal is highly affected by topographic variations: the
rougher the sample surface, the more the topography will affect the
friction signal. To differentiate between friction and topography, two
images are typically captured side-by-side. One is constructed from the
detector signal during the trace (left-to-right tip motion) of each line in
the raster scan, and the other is mapped during retrace (right-to-left tip
motion). Then one of the two images is inverted and subtracted from the
other. This reduces the topographic artifacts in the LFM signal, leaving
an image of primarily frictional forces.
Dynamic Lateral Force Microscopy (DLFM)
In Dynamic Lateral Force Microscopy (DLFM), the tip is in contact
with the sample, and the cantilever is oscillated parallel to the sample
surface (as opposed to perpendicular oscillation in AC Mode). The
topography is determined by cantilever deflection, as in contact mode.
However, the lateral oscillation is also monitored, such that the
amplitude and phase can be imaged, as in standard AAC Mode. DLFM
is used in polymer studies as it is very sensitive to changes in surface
properties such as friction and adhesion.
Magnetic Force Microscopy (MFM)
Magnetic Force Microscopy (MFM) probes the force between a
ferromagnetic tip and a ferromagnetic or paramagnetic sample to image
domain structures. The system detects changes in the phase of the
NOTE
DLFM requires MAC Mode or MAC III.