Electron Microscope
An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination.
As the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons , electron microscopes have a higher
resolving power than light microscopes and can reveal the structure of smaller objects.
A scanning transmission electron microscope has achieved better than 50 pm resolution in annular dark-field imaging mode[1] and
magnifications of up to about 10,000,000x whereas most light microscopes are limited by diffraction to about 200 nm resolution and useful magnifications below 2000x.
Electron microscopes have electron optical lens systems that are analogous to the glass lenses of an optical light microscope.
Electron microscopes are used to investigate the ultrastructure of a wide range of biological and inorganic specimens including
microorganisms , cells , large molecules,
biopsy samples, metals , and crystals . Industrially, electron microscopes are often used for quality control and failure analysis . Modern electron microscopes produce electron micrographs using specialized digital cameras and frame grabbers to capture the images.
Scanning Probe Microscope
An SPM (Scanning Probe Microscope) is an instrument used for studying surfaces at the nanoscale level.
SPMs form images of surfaces using a physical probe that touches the surface of a sample to scan the surface and collect data, typically obtained as a two-dimensional grid of data points and displayed as a computer image.
The first SPM was the scanning tunneling microscope (STM) developed at the IBM Research Lab in Zurich by Gerd Binnig and Heinrich Rohrer in 1982.
It was the first technology to be recognized as having atomic resolution capability.
An STM uses an electrical current between the microscope’s scanning tip and the sample to image the sample surface. Unfortunately, this means the surface of the sample must be conductive or semi-conductive, limiting the materials that can be studied. These limitations and others drove the invention of the first
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