Scanning Tunneling Microscopy (STM) is a scientific technique and type of microscopy that allows for the visualization and analysis of surfaces at the atomic level. It relies on the phenomenon of quantum tunneling, where electrons can pass through potential energy barriers.
In STM, a sharp conducting probe is brought extremely close to the surface being observed, with only a few angstroms of separation. The probe is scanned across the surface in a raster pattern, and a small voltage is applied between the probe and the surface. As the probe scans, electrons can tunnel between the probe and the surface, resulting in a measurable tunneling current.
This tunneling current is highly sensitive to the distance between the probe and the surface, allowing for the collection of topographic information. By adjusting the height of the probe to keep the tunneling current constant, a three-dimensional image of the surface can be generated with atomic resolution.
STM has revolutionized the study of surfaces, allowing scientists to observe individual atoms and molecules on materials such as metals, semiconductors, and insulators. It has been instrumental in understanding surface properties, surface defects, atomic scale processes, and even manipulating individual atoms.
Scanning tunneling microscopy has applications in various fields, including materials science, nanotechnology, surface chemistry, and solid-state physics. It has played a crucial role in the development of nanoscale devices, such as computer chips, and has contributed to advances in fields such as catalysis, molecular electronics, and nanomagnetism.
