Oxford Instruments Cypher SPM, Руководство пользователя

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Cypher SPM
User Guide
27
27 Preparing For Conductive AFM Imaging On The
Standard Scanner
This section explains the use of the ORCA cantilever holder. In practical terms, the ORCA cantilever
holder is simply a standard air cantilever holder with the addition of a current to voltage converting
amplifier.
Basic AC and contact mode imaging can be performed with the ORCA holder. One major difference
in its construction however is the use of the electrical connection to the cantilever spring clip. The
cantilever clip is used as a connection to the input of the current amplifier rather than a connection
to a bias voltage source. Because of this difference, the ORCA holder will not work for meas-
urement techniques where the tip needs to be biased.
Note: EFM (Electric Force Microscopy), Surface Potential - SKPM (Kelvin Probe Microscopy),
PFM( Piezoelectric Force Microscopy) imaging techniques require the use of the standard air
cantilever holder.
To prepare for imaging you need to do the following:
1. Zero the ORCA sample bias signal.
2. Prepare the sample.
3. Mount the cantilever.
27.1 Zeroing the ORCA sample bias signal
The signal path through the Cypher can pass through many stages of signal conditioning. Each par-
ticular circuit in the signal path can introduce a voltage offset which when added together can skew
the zero point of your measurement. The following adjustment should be made to your system
prior to imaging.
Page 190 of 243 27 Preparing for conductive AFM imaging on the standard scanner