Forskjell mellom versjoner av «Atomic Force Microscopy»
Linje 3: | Linje 3: | ||
Piezoelectric position control system. |
Piezoelectric position control system. |
||
The cantilever: V-shaped or single beam. V-shaped: high deflection sensitivity, not sensitive to torque. Single beam: vice-versa. |
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. |
Artifacts: drift, non-linear hysterisis of piezoelectric. |
||
− | ==Modes of operation== |
+ | ===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. |
||
− | =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. |
+ | ==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. |
+ | ==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. |
+ | ==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. |
Revisjonen fra 23. mai 2009 kl. 19:17
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.