EIRE2003 said:''The Scanning Tunnelling Microscope probes the density of states of a material''...
What does this actually mean?
EIRE2003 said:Ok, am I right in suggesting that the 'density of states' is, how closely packed the energy levels in an atom are, or is it how closely packed the energy levels in the material as a whole? That is, the energy gap between the valence band and the conduction band?
A Scanning Tunnelling Microscope (STM) is a scientific instrument used to image and manipulate materials at the atomic level. It works by scanning a sharp probe over the surface of a material, measuring the electrical current that flows between the probe and the material. This allows for the creation of high-resolution images of the material's surface, as well as the ability to manipulate individual atoms and molecules.
A Scanning Tunnelling Microscope (STM) works by using a sharp probe, usually made of tungsten, to scan over the surface of a material. The probe is positioned just a few nanometers above the surface and a small electrical bias is applied between the probe and the material. As the probe scans, it measures the flow of electrons (tunneling current) between the probe and the material. This information is then used to create an image of the material's surface.
The resolution of a Scanning Tunnelling Microscope (STM) is dependent on the size of the probe used. The smaller the probe, the higher the resolution. Currently, the best STMs have a resolution of around 0.1 nanometers, allowing for the visualization and manipulation of individual atoms and molecules.
A Scanning Tunnelling Microscope (STM) has a wide range of applications in various fields of science, including materials science, nanotechnology, and biology. It is used to study the surface structure of materials, investigate the properties of nanoparticles, and observe biological molecules such as DNA and proteins at the atomic level. It also has potential applications in data storage, as it can be used to read and write information at the atomic scale.
The main advantage of using a Scanning Tunnelling Microscope (STM) is its ability to image and manipulate materials at the atomic level. This allows for a deeper understanding of the properties and behavior of materials. Additionally, the images produced by an STM are of very high resolution, providing detailed information about the surface of a material. STMs also have the ability to operate in various environments, such as vacuum or liquid, making them versatile tools in scientific research.