Germer Experiment

Experiments conducted by Davisson and Germer have been seen to be depending on the diffraction pattern of electrons when these electrons have been scattered by the surface of Nickel. Depending on this hypothesis, Louis de Broglie has been seen to further develop these experiments to confirm wave-particle duality. Findings of these experiments have been known to bring about a huge revolution in quantum mechanics.

Background of Davisson and Germer Experiment

Depending on previous findings it has been seen that for all matter, if energy of a particle of selected matter can be denoted by E then frequency can be denoted by v and Plank’s constant can be denoted by h.

Thus, E = hv

Walter m. Elsasser has contributed to Davisson and Germer’s Experiments by defining that the wave of any particle of any matter can be identified and observed by electron scattering on different crystalline solids. Proposition made by Elsasser has been successful in explaining Davisson and Germer’s experiments. Davisson and Germer in 1927 fired some slow-moving electrons at a target which had been made of Nickel. Angular dependence of the electron which has been reflected was observed and identified to include same pattern of diffraction as Bragg predicted for X-Rays. Davisson and Germer’s experiment has been seen to establish hypotheses on matter-wave behavior by de Broglie. Combined with the Compton Effect described by Arthus Compton, Davisson and Germer’s experiment has been seen to establish hypotheses on wave-particle duality which has later been recognized as a fundamental step of quantum theory.

Davisson and Germer Experiment

Davisson has been seen to begin experimenting in 1921 in order to have knowledge on secondary electron emission and electron bombardment. Davisson continued research till 1925. Davisson, along with Charles H. Kunsman in 1923 has discovered that approximately 1.2% of electrons that have been bombarded on Tungsten have been bouncing back in elastic scattering. Depending on this result, Davisson established a theory that examining configuration of electrons of an atom can be done in an analogous manner based on the “Rutherford alpha particle scattering” of the nucleus. Based on this theory, Davisson changed the vacuum and used Nickel instead of Tungsten. Germer joined Davisson in 1924 with an objective to identify different angles of diffraction of electrons that have been bombarded. 

This experiment included firing an electron beam into a crystalline solid which has been Nickel. The surface of the crystal and source of the electron beam has been set at a perpendicular position to each other. The detector which has been used in this experiment was made to only accept elastically scattered electrons. In this experiment, air has entered the vacuum chamber and to omit chances of formation of oxide, Davisson and Germer have heated the specimen. Overheating of the specimen has caused polycrystalline structure of Nickel to change. This change later caused all electrons which have been bombarded to scatter by atoms of Nickel. Depending on this, in 1925 this experiment has generated a diffraction pattern that included uncorrelated and unexpected peaks based on heating process of crystalline solid. Davisson and Germer have been seen to change Nickel crystal and started experimenting again. Later, Davisson and Germer have realized that accidental discovery of electron diffraction due to heating the specimen has proved the hypothesis established by de Broglie. 

Application of This Experiment

Davisson and Germer’s experiment, though have been successful, vacuum tubes were not made available and reliable until the 1960s. The Electron diffraction process thus has not been developed since Davisson and Germer as scientists have been seen to use Low Energy Electron Diffraction (LEED) in exploring surfaces of crystalline solids. LEED has been seen to be a technique that can help in determining surface structure of different crystalline solids by bombarding electrons of low energy onto the surface. Observation of this technique has been seen to be done by using a fluorescent screen.

Conclusion of this Experiment

Conclusion of the Davisson and Germer experiment has been seen to depict that electrons also have a wave nature and thus it provided confirmation of the hypothesis of de Broglie. Electrons that have been included in these experiments have been identified to be scattered by using Bragg’s law to have maximum scattering. These experiments have produced a wavelength of 0.166 nm whereas 0.168 nm wavelength has been observed in an electron having almost 55eV of kinetic energy with an angle of approx 51 degrees. These criteria of angle and voltage can produce highest intensity in wavelengths and thus wavelength of an electron being 0.168 nm depicts that electron is having highest intensity. These conclusions have been helpful in establishing the fact that electrons of any matter also have a wave nature.

Conclusion

This article has concluded by clarifying the theory of Davisson and Germer’s experiment. Background of Davisson and Germer’s experiment being concluded in this article can be helpful in understanding the contribution of different scientists to these experiments. A detailed outline of the Davisson and Germer experiment has also been concluded in this article. This outline can be helpful in having a clear idea of how these experiments were conducted. Application and conclusion of these experiments have also been concluded in this article.