In SKPM, the conductive cantilever is scanned over the surface area of the analyzed sample at a constant height to display its function of operation. The definition of the function of work is based on the measurement of electrostatic forces between the AFM tip and the sample being analyzed. This app was obtained from AFM.
SKPM is similar to electrostatic force microscopy (or EFM), which is often used in laboratories to measure special resolution of surface potential maps. EFM images can be created by measuring cantilever oscillations, changing phase and frequency in response to electrostatic gradients, which is similar to the methods adopted by SKPM.
Both methods are similar in their approach to the analysis of samples, that is, both of them use a non-contact cantilever, however there are serious differences between the two applications.
The cantilever AFM is a reference electrode, i.e. It is stable and has a well-known electrode potential. It forms a capacitor with the surface of the sample, by which it is scanned from the side with constant separation. At this frequency, an alternating current (AC) voltage is usually superimposed, since the cantilever is not controlled at its mechanical resonant frequency.
The work surface itself is associated with many surface phenomena and can be observed on atomic or molecular scales. The microscope used by the researcher will analyze the sample, measuring its catalytic activity; surface reconstruction; alloying and bending of semiconductor strips; charge capture in dielectrics and corrosion.
Then the information obtained by volume will provide the researcher with data on the composition and electronic state of local structures on the surface in the form of a solid sample. When there is a DC potential difference between the tip and the sample surface, an AC + DC voltage offset will cause the cantilever to vibrate.
This is usually detected using scanning probe microscopy techniques, usually using a diode laser and a four-quadrant detector. A zero circuit is then used to control the DC potential of the tip to a value that minimizes vibration. The map of the potential of direct current in comparison with the coordinate position and produce an image of the function of the analyzed surface.
The principles of SKPM are similar to the principles of Enhanced EFM in the sense that they both work from the DC feedback loop and require the use of metal cantilevers to conduct electricity. A constant DC bias providing a zero level of force provides the researcher with a measurement of the surface potential of the sample.
EFM directly measures the force generated on a charged tip by an electric field from the surface. This application works similarly to magnetic force microscopy, since it measures the frequency or amplitude of oscillations of a cantilever to detect the electric field of a sample. The main difference between the two is that the MFM method measures magnetic force gradients instead of electrostatic force gradients.
In EFM, force arises due to the attraction of repulsion of separated charges using long-range applications. The cantilever oscillates and is not in contact with the surface area of the sample.
The main difference between the EFM and SKPM methods is how the signal is obtained from the blocking amplifier. This signal is used to measure the surface potential of the sample. EFM is also much more sensitive to topographical artifacts than SKPM.
