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Dark-field microscopy (also called dark-ground microscopy) describes microscopy methods, in both light and electron microscopy, which exclude the unscattered beam from the image. Consequently, the field around the specimen (i.e., where there is no specimen to scatter the beam) is generally dark. In optical microscopes a darkfield condenser lens ...
Field-emission microscopy. Field-emission microscopy ( FEM) is an analytical technique that is used in materials science to study the surfaces of needle apexes. [1] [2] The FEM was invented by Erwin Wilhelm Müller in 1936, [3] and it was one of the first surface-analysis instruments that could approach near- atomic resolution .
Bacterial cellular morphologies are the shapes that are characteristic of various types of bacteria and often key to their identification. Their direct examination under a light microscope enables the classification of these bacteria (and archaea ). Generally, the basic morphologies are spheres (coccus) and round-ended cylinders or rod shaped ...
t. e. Scanning probe microscopy ( SPM) is a branch of microscopy that forms images of surfaces using a physical probe that scans the specimen. SPM was founded in 1981, with the invention of the scanning tunneling microscope, an instrument for imaging surfaces at the atomic level. The first successful scanning tunneling microscope experiment was ...
Conoscopic interference pattern. A conoscopic interference pattern or interference figure is a pattern of birefringent colours crossed by dark bands (or isogyres ), which can be produced using a geological petrographic microscope for the purposes of mineral identification and investigation of mineral optical and chemical properties.
An account of the early history of scanning electron microscopy has been presented by McMullan. [2] [3] Although Max Knoll produced a photo with a 50 mm object-field-width showing channeling contrast by the use of an electron beam scanner, [4] it was Manfred von Ardenne who in 1937 invented [5] a microscope with high resolution by scanning a very small raster with a demagnified and finely ...
Reproduction of an early electron microscope constructed by Ernst Ruska in the 1930s. Many developments laid the groundwork of the electron optics used in microscopes. [2] One significant step was the work of Hertz in 1883 [3] who made a cathode-ray tube with electrostatic and magnetic deflection, demonstrating manipulation of the direction of an electron beam.
Two Leica oil immersion microscope objective lenses; left 100×, right 40×. The objective lens of a microscope is the one at the bottom near the sample. At its simplest, it is a very high-powered magnifying glass, with very short focal length. This is brought very close to the specimen being examined so that the light from the specimen comes ...