scanning tunneling microscope
(noun)
An instrument for imaging surfaces at the atomic level.
Examples of scanning tunneling microscope in the following topics:
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Quantum-Mechanical View of Atoms
- Atoms in solid states (or, to be precise, their electron clouds) can be observed individually using special instruments such as the scanning tunneling microscope.
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Specialty Microscopes and Contrast
- There are many types of microscopes: optical microscopes, transmission electron microscopes, scanning electron microscopes and scanning probe microscopes.
- One way to group microscopes is based on how the image is generated through the microscope.
- Microscopes can also be classified based on whether they analyze the sample by scanning a point at a time (scanning electron microscopes), or by analyzing the entire sample at once (transmission electron microscopes).
- Scanning Electron Microscopes: Referred to as SEM, these microscopes look at the surface of objects by scanning them with a fine electron beam .
- Atomic Force Microscopy: The AFM is a scanning probe type of microscopy with very high resolution and is one of the foremost tools for imaging at the nanoscale.
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Electron Microscopes
- An electron microscope is a microscope that uses an electron beam to create an image of the target.
- It has much higher magnification or resolving power than a normal light microscope.
- Let's first review how a regular optical microscope works .
- Electron microscopes are very useful as they are able to magnify objects to a much higher resolution.
- Diagram of the basic components of an optical microscope and an electron microscope.
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Enhancement of Microscopy
- Microscopes are used to view objects that cannot be seen with the naked eye.
- You have probably used an optical microscope in a high school science class.
- Two kinds of electron microscopes are:
- Transmission electron microscope (TEM): The TEM sends an electron beam through a thin slice of a specimen.
- Scanning electron microscope (SEM): The SEM shows details on the surface of a specimen and produces a three-dimensional view by scanning the specimen. shows an SEM image of pollen.
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Diffraction Revisited
- Experiments are usually performed using a transmission electron microscope or a scanning electron microscope.
- Typical electron diffraction pattern obtained in a transmission electron microscope with a parallel electron beam.