Special modes

Intermodulation Electrostatic Force Microscopy (ImEFM) is more sensitive than standard Kelvin Probe Force Microscopy (KPFM). ImEFM uses resonance to enhance sensitivity, and it works very close to the surface without lift-mode, thereby giving higher resolution.  You can scan faster than standard KPFM with the same signal-to-noise ratio.  ImEFM works without voltage feedback so you are free to apply an arbitrary DC voltage to the tip and study how the electrostatic force responds to this 'gating' potential.

click on image:  ImEFM on graphehe, showing surface potential in Volts over monolayer (lightest), bilayer and trylayer (darkest).  Scan size is 4um.

Read more in the software manual

See publication

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Intermodulation Frictional Force Microscopy (ImFFM) uses torsional resonance to achieve very high tip velocity (vmax ~ 5 cm/sec) while measuring frictional forces with very high spatial resolution (~ 10 nm). At each image pixel you can observe how frictional force depends on the amplitude of tip oscillation, or velocity of the sliding tip. Both conservative dissipative lateral forces are seen to change as the sliding velocity increases, revealing the transition from stick-slip to free-sliding friction.

click on image:  ImFFM on HOPG. Dynamic force quadrature curves FI(A) and FQ(A) are shown for the latteral, or frictional force at three pixels marked in the image. The bands in the image are due to changing the feedback setpoint, where darker corresponds to higher load force.   Scan size is 1um.

 

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