In the year , two American physicists C.J Davisson and L.H Germer conducted an experiment to explain the wave nature of electrons. Description: Davisson and Germer’s experiment was in the support of de Broglie’s hypothesis. They demonstrated the diffraction of electron beam similar to. Davisson Germer experiment with observations, Co-relating Davisson Germer experiment and de Broglie are provided here. Learn more about it at BYJU’S.
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The Davisson-Germer experiment demonstrated the wave nature of the electron, confirming the earlier hypothesis of deBroglie. Putting wave-particle duality on a firm experimental footing, it represented a major step forward in the development of quantum mechanics.
The Bragg law davisoh diffraction had been applied to x-ray diffraction, but this was the first application to particle waves.
Davisson and Germer designed and built a vacuum apparatus for the purpose of measuring the energies anv electrons scattered from a metal surface.
Davisson Germer Experiment – Electron Diffraction
Electrons from a heated filament were accelerated by a voltage and allowed to strike the surface of nickel metal. The electron beam was directed at the nickel target, which could be rotated to observe angular dependence of the scattered electrons.
Their electron detector called a Faraday box experimenh mounted on an arc so that it could be rotated to observe electrons at different angles.
It was a great surprise to them to find that at certain angles there was a peak in the intensity of the scattered electron beam.
Davisson–Germer experiment – Wikipedia
This peak indicated wave behavior for the electrons, and could be interpreted by the Bragg law to give values for the lattice spacing in the nickel crystal. The experimental data above, reproduced above Davisson’s article, shows repeated peaks of scattered electron intensity with increasing accelerating voltage. This data was collected at a fixed scattering angle.
Using the Bragg law, the deBroglie wavelength expression, and the kinetic energy of the accelerated electrons gives the relationship.
For that lattice spacing and scattering angle, the relationship for wavelength as a function of voltage is empirically. Then what gives the daviosn, fourth and sixth peaks? Perhaps they originate from a different set of planes in the crystal. Those peaks satisfy a sequence 2,3,4, suggesting that the first peak of that series would have been at 5.
That corresponds to an electron wavelength of 0. I don’t know if that makes sense.
I need to look at the original article. Davisson-Germer Experiment Davisson, C.
Index Great experiments of physics Reference Rohlf Ch 5.