Forskjell mellom versjoner av «Atomic Force Microscopy»
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===Modes of operation=== |
===Modes of operation=== |
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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. |
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==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. |
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==Tapping mode== In the semi-contact region of the potential energy curve. |
==Tapping mode== In the semi-contact region of the potential energy curve. |
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==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. |
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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.
