Forskjell mellom versjoner av «Atomic Force Microscopy»
| Linje 1: | Linje 1: | ||
| − | + | ===Fun facts=== |
|
High vacuum is not necessary. |
High vacuum is not necessary. |
||
Piezoelectric position control system. |
Piezoelectric position control system. |
||
| Linje 6: | Linje 6: | ||
Artifacts: drift, non-linear hysterisis of piezoelectric. |
Artifacts: drift, non-linear hysterisis of piezoelectric. |
||
| − | + | ===Modes of operation=== |
|
It is the displacement of the probe tip at the end of the cantilever that is measured. |
It is the displacement of the probe tip at the end of the cantilever that is measured. |
||
Revisjonen fra 23. mai 2009 kl. 19:18
Fun facts
High vacuum is not necessary. Piezoelectric position control system. The cantilever: V-shaped or single beam. V-shaped: high deflection sensitivity, not sensitive to torque. Single beam: vice-versa. Material used: diamond, tungsten, silicon. Artifacts: drift, non-linear hysterisis of piezoelectric.
Modes of operation
It is the displacement of the probe tip at the end of the cantilever that is measured.
Contact mode
In the contact region of the potential energy curve, repulsive forces dominate. Two ways: Set height constant and measure repulsive force or set force constant and measure height.
Tapping mode
In the semi-contact region of the potential energy curve.
Non-contact mode
In the non-contact region of the potential energy curve, attractive forces dominate and are measured. What is observed is a an increase in the amplitude of the oscillations of the vibrating probe, translated into a change in attractive forces.
