atomjõumikroskoopia

Atomjõumikroskoopia, known in English as Atomic Force Microscopy (AFM), is a high-resolution scanning probe microscopy technique that allows for the imaging of surfaces at the atomic level. It operates by scanning a sharp tip, typically made of silicon or silicon nitride, across the surface of a sample. The tip is attached to a cantilever, a tiny flexible beam. As the tip encounters variations in the sample's topography, it moves up and down. This movement is detected by a laser beam that is reflected off the back of the cantilever onto a photodetector. The resulting changes in the laser's position are translated into a topographical map of the sample's surface.

AFM can operate in various modes, including contact mode, tapping mode, and non-contact mode. In contact mode, the tip is in constant physical contact with the surface, which can be useful for imaging rigid samples but may also lead to surface damage. Tapping mode involves oscillating the cantilever and bringing it into intermittent contact with the surface, reducing lateral forces and minimizing damage. Non-contact mode keeps the tip a small distance above the surface, detecting interatomic forces. This technique is versatile and can be used to image a wide range of materials, including insulators and conductors, and can operate in air, liquid, or vacuum. Beyond topography, AFM can also measure various surface properties such as friction, adhesion, magnetic forces, and electrical properties through specialized tips and detection schemes.