F
ORCE
M
ODULATION
69
Force Modulation
The Force Modulation mode is an extension of the Static force mode. The
static force acting on the cantilever is still used to produce a topography
image of the sample. Simultaneously, the cantilever is excited and the result-
ing vibration amplitude measured. The vibration amplitude depends on the
drive amplitude, the stiffness of the cantilever and, most importantly, the
stiffness of the tip-sample contact. Thus, the force modulation mode can be
used to produce material contrast when there is a significant difference in
the stiffness of the tip-sample contact of these materials. This section gives
a brief description of how to operate the easyScan 2 AFM in force modula-
tion mode. For a more detailed description of the parameters that you can
set, refer to section
Proceed as follows to operate the easyScan 2 AFM in the Force Modulation
mode:
- Select a cantilever that has a spring constant that is suitable for the sample
stiffness that you expect.
Good results were obtained with LFMR-type cantilevers. The FMR type
cantilever, which is explicitly sold for Force Modulation mode measure-
ments, cannot be used due to its insufficient width.
- Install the cantilever as described in section
- Select the Force Modulation mode in the Operating mode panel.
- If necessary, verify the force Set point in the Z-Controller panel.
Folded back: Frequency spectrum with phase shift folded back over the +90° limit
Summary of Contents for easyScan 2 AFM
Page 1: ...Operating Instructions easyScan 2 AFM Version 1 6...
Page 7: ...7...
Page 86: ...AFM THEORY 86 Scanner coordinate system x y...
Page 159: ...THE SCRIPT CONFIGURATION DIALOG 159 This page was intentionally left blank...
Page 160: ...AUTOMATING MEASUREMENT TASKS 160 This page was intentionally left blank...
Page 161: ...THE SCRIPT CONFIGURATION DIALOG 161 This page was intentionally left blank...
Page 163: ...163 Window Operating windows Imaging 120 Positioning 115 Report 153 Spectroscopy 128...
Page 164: ......