Diffraction of Electrons by a Crystal of Nickel. CLINTON J. DAVISSON, LESTER H. GERMER.
Diffraction of Electrons by a Crystal of Nickel
Diffraction of Electrons by a Crystal of Nickel

Diffraction of Electrons by a Crystal of Nickel

"Dr. Davisson, When you found that electron beams touching crystals give rise to phenomena of diffraction and interference, this signified in itself a discovery that widened essentially our knowledge of the nature of electrons. But this discovery has proved to be of still greater importance. Your researches concerning these phenomena resulted in your presenting the first positive, experimental evidence of the wave nature of matter." -Nobel Prize Presentation Speech

FIRST EDITION IN ORIGINAL WRAPPERS of Davisson and Germer’s confirmation of de Broglie’s hypothesis that matter has wave-like properties.

“A 1927 paper in the Physical Review demonstrated that particles of matter can act like waves, just as light waves sometimes behave like particles. Clinton Davisson and Lester Germer of the Bell Telephone Laboratories, then in New York, found that electrons scatter from a crystal in the same way that x rays do. The work began as a result of a laboratory accident and ultimately earned Davisson a Nobel Prize.

“In 1924, Louis de Broglie... proposed that matter, like light, has a dual nature. The next year, graduate student Walter Elsasser of the University of Göttingen in Germany proposed a way to test it: If electrons do have a wave nature, they should, like light, exhibit wave phenomena such as diffraction. In one form of diffraction, a light beam passing through a regular series of holes or slits, called a grating, exhibits “dark spots” in directions where the wave troughs coming from some holes cancel the peaks coming from others. “Bright spots” appear in directions where the peaks reinforce one another. A beam of tiny marbles, as electrons were conceived of until this point, could never show such cancellation and enhancement.

“By chance, Davisson and his junior partner Germer were well-positioned to quickly follow Elsasser’s suggestion. They had been attempting to probe the structure of the atom by firing low-speed electrons at nickel and measuring the scatter. Their experiments weren’t turning up anything of interest, and in 1925 they were saved from frustration and ultimately obscurity by an accident. Their equipment broke, and extreme heating recrystallized their nickel target into a few large crystals, where previously there had been many smaller ones. Their data, showing the amount of scattered electrons at each detector position, began exhibiting some intriguing peaks.

“It was only later, when Davisson discussed his results with physicists during his 1926 summer vacation in England, that he learned of de Broglie’s theory and realized that his data likely contained the world’s first glimpse of electron diffraction. The atoms in the recrystallized nickel had acted as a grating. Following this realization, Davisson and Germer began a deliberate search for diffraction patterns, especially the peaks in their data plots that would indicate extra electrons scattering in specific directions. After some disappointing initial results, they found a single peak that agreed both with de Broglie’s theory and with separate experiments using x rays in place of electrons. Eventually they found 30 peaks, 29 of which could be explained by diffraction. One was left unexplained, and they failed to find eight additional peaks that they had expected to appear.

“The team published a short paper in Nature in early 1927 and then a more complete article later that year in the Physical Review. George Paget Thomson of the University of Aberdeen in Scotland published his own experimental proof of electron diffraction just a month later and shared the 1937 Nobel Prize in physics with Davisson” (Chelsea Wald, American Physical Society).

Particle Physics: One Hundred Years of Discoveries: “Discovery of the diffraction of electrons by crystals. Confirmation of the wave properties of moving electrons. Nobel Prize to C.J. Davisson awarded in 1937 and to co-winner G.P. Thomson ‘for their experimental discovery of the diffraction of electrons by crystals.’”

IN: The Physical Review, Vol 30, No. 6, December 1927, pp. 705-740. Minneapolis, MN: The American Physical Society, 1927. Octavo, original wrappers; custom box. Some fading to spine and wrapper edges; otherwise fine. RARE in wrappers.

Price: $2,300 .

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