April 2011 SPM Issue Cover Picture and Story
Cover Story
Atomic Point Defects with AFM in Liquid
The cover shows three sequential image pairs of height (left/green) and phase (right/blue) taken of a single crystal of calcite (CaCO3) in water with the Cypher Atomic Force Microscope from Asylum Research. The repeat of the defects in both the height and phase images demonstrates true atomic scale resolution at a level previously not possible in liquid or ambient AFM. The images were taken in AC mode; open loop (corrected for piezo creep and drift); scan size: 10 nanometers; Z scale: 100 picometers; phase scale: 60 degrees.
Several technological advances have enabled this unprecedented resolution. First is the improved signal-to-noise ratio from the use of ultra-small cantilevers with much higher resonant frequencies in liquid. These images were taken with a 55-µm long prototype AC-60 cantilever with a resonance frequency of about 1 MHz in liquid (kindly provided by Olympus). Cypher can use levers as short as 10 µm long. Second, the optical lever noise floor on the Cypher AFM has been pushed to 25 fm/rtHz, allowing the measurement to remain thermally limited even with stiff cantilevers and very small amplitudes. The cantilever amplitude for this image sequence was 100 picometers. Finally, Cypher’s exceptional open-loop noise (~5 picometers in X, Y, and Z) allows the stability to image at this scale, even on a scanner with a 30 µm lateral range.
The World’s Highest Resolution AFM
"Cypher is by far the best, most stable and most configurable AFM I have ever used." Andras Kis, EPFL.
"Our new Cypher system is exceptional in terms of performance, automation, imaging speed and ease of use." Brian Huey, University of Connecticut.
"Cypher is one fantastic AFM. It sets the standard for both resolution and ease of use." Ray Dagastine, University of Melbourne.
Please go to MyAsylumAFM.com for more comments from Cypher users.
Ask us about Asylum's legendary product and applications support, and our two-year bumper-to-bumper warranty and 6-month money-back satisfaction guarantee. See the Cypher video at www.cypherafm.com, visit us at www.AsylumResearch.com or request a quote at sales@AsylumResearch.com.
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