What is a Scanning Tunneling Microscope?

Scanning Tunneling Microscope is abbreviated as STM. As a scanning probe microscopy tool, a scanning tunneling microscope allows scientists to observe and locate individual atoms, and it has a higher resolution than its comparable atomic force microscope.

Scanning tunneling microscope

Scanning Tunneling Microscope is abbreviated as STM. It acts as a scanning probe

STM enables humans to observe, for the first time in real time, the arrangement of individual atoms on the surface of matter and physical and chemical properties related to surface electronic behavior. In surface science,

The working principle of a scanning tunnel microscope is surprisingly simple. Just like a stylus swiping through a record, a probe slowly passes through the material to be analyzed (the tip of the needle is extremely sharp and consists of only one atom). A small charge is placed on the probe, and a current flows from the probe through the entire material to the underlying surface. As the probe passes a single atom, the amount of current flowing through the probe varies, and these changes are recorded. When an electric current flows through an atom, it fluctuates, so that its contour can be probed very carefully. After many circulations, by drawing the fluctuation of the amount of current, one can get a composition

With the invention of the scanning tunneling microscope in 1981, physicists made a breakthrough.

The structure of the scanning probe plays an important role in scanning the surface of the sample with a scanning tunneling microscope (STM). For example, the radius of curvature of the needle tip is a key factor affecting the lateral resolution; the size, shape and chemical identity of the needle tip affect not only the resolution of the STM image, but also the measurement of the electronic structure. Therefore, accurately observing and describing the geometry and electronic characteristics of the needle tip has important reference value for the evaluation of experimental quality. Researchers of scanning tunneling microscope (STM) have used some other techniques to observe the microscopic morphology of scanning tunneling microscope (STM) needle tips, such as SEM, TEM, FIM, etc. SEM generally can only provide micron- or sub-micron-level morphological information. Obviously, observation of atomic-level microstructure is far from enough. Although high-resolution TEM can be used to obtain atomic-level sample images, it is difficult to observe the tip of a scanning tunneling microscope (STM), and its atomic-level resolution is only barely achievable. Only FIM can observe the morphology of the tip of a scanning tunneling microscope (STM) metal tip with atomic resolution, thus becoming an effective observation tool for scanning tunneling microscope (STM) tip. Sakurai Leif and others at Tohoku University in Japan made use of this advantage of FIM to make a FIM-STM combined device (researchers call it FI-STM), which can be used to observe scanning tunneling microscope (STM ) Scanning the geometry of the needle tip, which allows people to perform experiments with the state of the scanning tunnel microscope (STM) needle tip, thereby improving the efficiency of using scanning tunnel microscope (STM) instruments ^[1] .