User`s guide

AC Modes 6
Agilent 5500 SPM User’s Guide 112
2
In the ACAFM Controls dialog box, choose MAC as the Drive
Mechanism.
Top MAC Mode
In Top MAC Mode AFM, the driver coil is located in the nose assembly
(Figure 78). This configuration provides better tip response when
imaging thick samples which can lessen the magnetic field oscillating
the tip. Any sample plate can be used for Top MAC imaging.
Figure 78 Top MAC nose assembly
Q Control
An oscillating cantilever in AC mode is influenced by complex
interaction forces between it and the surface. By carefully setting system
parameters the system can be made to operate entirely in the regime of
net-attractive forces, thereby reducing the effect of the probe tip on the
sample. The range in which the parameters have to be adjusted can be
narrow, however, making it difficult to maintain in real operation.
Q Control is a method that reduces damping of the system, increasing
the quality factor of the oscillating cantilever. Enhanced resonance
allows imaging with very low force and high phase sensitivity. The