Operating instructions

MEASUREMENT MODES
54
Measurement modes
This chapter instructs you on how to use the Dynamic Force, Static Force,
Phase contrast, the Force Modulation, and Spreading Resistance modes. If
you are unfamiliar with the Atomic Force Microscopy Technique, it is rec-
ommended to first read the chapter AFM Theory (p.70).
The amount of available modes depends on the Scan head and the available
modules built into the easyScan 2 Controller. The modules required to be
able to use a certain operating mode are listed in table Operating modes and
required modules. The modes can be divided into the static operating modes
that control the Z-position control using the Cantilever deflection, the
dynamic operating modes that control the Z-position using the vibration
amplitude.
Static Force
In the Static Force mode, the ‘static’ deflection of the cantilever is used as
the error signal for the Z-position Controller. The Set point in Newton is
calculated by multiplying the deflection with the spring constant of the
selected cantilever. In order to minimize tip/sample wear, the force set
point should be made as small as possible. In some cases, even a negative set
point (i.e. an adhesive force) may work, but when the tip momentarily loses
contact with the sample due to some disturbance, the Z-Controller will
always fully retract the cantilever from the sample. Moreover, working in
this range may cause image artefacts due to instabilities in the tip-sample
contact.
Operating mode Required modules
Static force AFM Basic
Dynamic force AFM Basic, AFM Dynamic
Phase contrast AFM Basic, AFM Dynamic, AFM Mode Extension
Force Modulation AFM Basic, AFM Dynamic, AFM Mode Extension
Spreading Resistance AFM Basic, AFM Dynamic, AFM Mode Extension
Operating modes and required modules