page_title: Electron diffraction
section_title: History
hierarchical_section_title: Electron diffraction / History
context_page_description: Electron diffraction refers to the wave nature of electrons. However, from a technical or practical point of view, it may be regarded as a technique used to study matter by firing electrons at a sample and observing the resulting interference pattern. This phenomenon is commonly known as wave–particle duality, which states that a particle of matter can be described as a wave. For this reason, an electron can be regarded as a wave much like sound or water waves. This technique is similar to X-ray and neutron diffraction.
  Electron diffraction is most frequently used in solid state physics and chemistry to study the crystal structure of solids. Experiments are usually performed in a transmission electron microscope, or a scanning electron microscope as electron backscatter diffraction. In these instruments, electrons are accelerated by an electrostatic potential in order to gain the desired energy and determine their wavelength before they interact with the sample to be studied.
  The periodic structure of a crystalline solid acts as a diffraction grating, scattering the electrons in a predictable manner.
context_section_description: The de Broglie hypothesis, formulated in 1924,  predicts that particles should also behave as waves. De Broglie's formula was confirmed three years later for electrons (which have a rest-mass) with the observation of electron diffraction in two independent experiments.  At the University of Aberdeen, George Paget Thomson and his colleague A Reid passed a beam of electrons through thin film of celluloid and observed the predicted interference patterns. Around the same time at Bell Labs, Clinton Joseph Davisson and Lester Halbert Germer guided their beam through a crystalline grid (see Davisson–Germer experiment).  In 1937, Thomson and Davisson shared the Nobel Prize for Physics for their (independent) discovery.
caption: Lester Germer (right) with Clinton Davisson in 1927
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