Forums
Bruker Media
Community Media
Bruker AFM Probes
SPM Digest
Application Notes
NanoTheater
Website
中文
Brochures & Datasheets
Publications
Probes Catalog
Events
Manuals & Documentation
Presentations
Guide to AFM Modes
News
Journal Club
Webinars & Video
Nanovations
Other
Hi Friends,
The mean value of Potential shifts 0.5~1 V when the lift distance between the tip and the sample increases or decreases 50nm.
I have tried this on various samples, e.g. sample chuck, n-type Si wafer, Pt coating, isolators. All the results show the same, that the mean value of potential (or data center of potential scope) depends on the lift distance.
I don´t understand why Mean value of Potential depend on the lift distance. If the sample chuck and cantilever is electrically connected, the ´contact potential difference´should be constant. Is there any setting problems with my machine? Could you please leave our idea here?
Information about my AFM: Dimension 3100, Nanoscope 4 controller, tip: SCM-PIT ; ´AC+DC´set to ´tip´; ´Bias´set to ´Sample´.
It seems that the Pt/Ir coating of the tip is worn already. So the Si material appears. The semiconductor´ bands bend when it measures. Therefore, a dependence between potential and lift distance occurred.
This dependence disappeared when I changed a new tip.
What is your idea about it?