Hysteresis mapping
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Try to acquire hysteresis loops fast:)
If your drift is 1 nm/min and loop takes 10 s, you are safe since signal generation volume is ~10-30 nm (caveat is that res frequency can shift, but for low frequency PFM it is not a big deal).
Controllers such as Omicron, Asylum, and Nanonis allow you to introduce lienar correction for stationary drift, but modern platforms are good enough to suppress it.
E.g. on MultiMode in a good room we were able to collect 6 hour SS-PFM scans over 300 nm region with small drifts (miniscule distortion) -
As Sergei mentions, having a thermally stable system is important. This can be accomplished with good microscope design and a temperature controlled room. The real world involves microscopes that have metal components and other pieces that move when the temperature changes. To compensate for this, active drift correction can be used.
The movie in the link below isn't SSPFM, but it illustrates the results of this type of active compensation. The movie shows a scan of a 250 nm scan of gold on glass was taken at 1 Hz (linescan rate) and at 256x256 pixels. The acoustic hood was left open for 12 hours and closed at the start of imaging. These images were made in attractive mode to keep the tip as constant as possible, as evidenced by comparing the first and last frames.
This movie shows images acquired over the period of one week.
http://www.AsylumResearch.com/ftp/outgoing/20090522_ImageStabilization.zip
File size is ~30MB. -
Given that a typical loop rarely takes more than a minute, you would not have any serious problem even with a drift as large as 10 nm/min (your tip-sample contact area is of the order of 10 nm). If your sample requires slow loop measurements (several minutes or more per loop) compensation of a thermal drift would be helpful.