Nanosurf easyScan 2 AFM, Operating Instructions Manual

Page: 70 / 164

M
EASUREMENT MODES
70
- In the Operating mode panel, click to measure the frequency
characteristic of the cantilever.
- Note the cantilever resonance frequency from the sweep chart and set
‘Excitation frequency’ to this value.
- Set ‘Excitation amplitude’ to the desired modulation amplitude.
- Increase the excitation amplitude when no Force Modulation signal can
be measured.
To display the measurement results:
- Click in the Chart bar to create a new chart in the Imaging window.
- If necessary, increase the size of the window to make space for the new
chart.
- Select the ‘Color map’ chart type by .
- Select the ‘Amplitude’ signal by .
Spreading Resistance
The Spreading Resistance mode is an extension of the static force mode.
The static force acting on the cantilever is used to produce a topography
image of the sample. Simultaneously, changes in the spreading resistance
from the cantilever tip to a ground contact on a sample can be imaged by
measuring changes in tip current whilst a fixed voltage is applied to the tip.
This section gives a brief description of how to operate the easyScan 2 AFM
in Spreading Resistance mode. For a more detailed description of the
parameters that you can set, refer to section
The Operating mode panel
(p.95).
Proceed as follows to operate the easyScan 2 AFM in the Spreading Resist-
ance mode:
- Electrically connect the sample to the Ground connector on the easyScan
2 AFM Scan head (figure Parts of the scan head (p.18)) via a 100 kOhm
resistor, in order to prevent damage to the tip due to an excessive current.