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American physicist Clinton Joseph Davisson won the Nobel Prize in physics in 1937. Davisson found that electrons could be diffracted by crystals just like X rays. He also proved they can show wavelike structure.
Clinton J. Davisson (1881-1958), American physicist and Nobel laureate. Davisson made major contributions to understanding the diffraction of electrons by crystals and shared the 1937 Nobel Prize in physics with British physicist Sir George Paget Thomson for their independent proof of the wave properties of electrons.
Born in Bloomington, Illinois, Davisson entered the University of Chicago in 1902. He left to teach physics at Purdue University in 1903 and 1904. In 1905 he became a physics instructor and research assistant at Princeton University. Returning to the University of Chicago for summer sessions, Davisson finally completed his B.S. degree in physics in 1908. After earning a Ph.D. degree in physics from Princeton University in 1911, Davisson accepted an appointment as an assistant professor of physics at the Carnegie Institute of Technology.
In 1917, during World War I (1914-1918), Davisson took leave from the Carnegie Institute to work on a military telecommunications project at the engineering department of the Western Electric Company Laboratories, which later became the Bell Telephone Laboratories. After the war, he decided to remain at the laboratories, which guaranteed him freedom to do full-time research, an uncommon opportunity in commercial laboratories at that time. Davisson retired from Bell in 1946 and accepted a position as a visiting professor of physics at the University of Virginia in Charlottesville, where he remained until his retirement in 1954.
At Western Electric, Davisson pursued his interest in thermionics, the emission of electrically charged particles, or ions, from conducting materials such as metals heated to high temperatures. His experiments in thermionics revised classic theory on conduction and the thermal energy of electrons.
In 1925 an accidental explosion of a bottle of liquid air (air that has been cooled and compressed until it becomes a liquid; see Matter, States of) in Davisson's laboratory put him on the path to a great discovery. The explosion allowed a piece of nickel Davisson was using as a target for high-speed electrons to become oxidized—that is, for the outer nickel atoms to bond with oxygen atoms (see Chemical Reaction). After cleaning the target by means of prolonged heating, Davisson found that although it had originally been composed of many small crystals, it had now formed several large crystals. He continued with the experiment but found that the electrons that now bounced off the target were bouncing off at completely different angles than before. Davisson attributed the change only to the different way the target was reflecting the electrons, but a 1926 meeting of physicists convinced him to search for a further cause. There he first learned in detail about the hypothesis of French physicist Louis de Broglie that any material particle (see Matter) could behave like a wave (see Wave Motion). Joining forces in 1926 with American physicist Lester Halbert Germer, Davisson searched for evidence of interference—that is, the effects resulting from adding waves together—between the electrons as they bounced off the target; an interference pattern would be present only if the electrons were behaving like waves—purely material particles cannot produce interference patterns.
In 1927 Davisson showed that, like electromagnetic waves (see Electromagnetic Radiation), electrons can produce interference patterns and be diffracted by crystals. His experiments proved that electrons can show wavelike behavior and helped show that all matter can show wavelike behavior since electrons are one of the subatomic particles that make up all matter. For this discovery, Davisson was awarded the Comstock Prize of the National Academy of Sciences in 1928.
In the 1930s Davisson's research continued to focus on electron waves, especially in their application to crystal physics and electron microscopy (see Microscope), and helped to develop a technique for electron focusing. Davisson's later research focused on the theory and application of electron optics, the theory of electronic devices (see Electronics), and solid-state physics, also known as condensed-matter physics.