The Scattering of Electrons from Single Crystals of Nickel

Abstract

IN a letter to NATURE (vol. 119, p. 558; April 16, 1927, hereafter cited as loc. cit), Messrs. Davisson and Germer have communicated the results of some very interesting experiments on the scattering of electrons from single crystals of nickel. They show that the distribution of scattered electrons, which have only lost a small fraction of their energy, depends on the voltage, and is in accordance with the symmetry of the crystal. The authors explain their results approximately on the basis of the Einstein - de Broglie theory of the wave electron, in a similar manner to that suggested by Elsasser (Naturwiss., 13, p. 711, 1925) in explanation of earlier experiments of Davisson and Kunsman (Phys. Rev., 22, p. 243, 1923). In particular, the explanation given is that electrons of velocity v are scattered by the nickel crystal in very nearly the same directions as those in which an electromagnetic wave of wave - length λ_e = h/mv would be diffracted by the cross grating formed by the uppermost layer of atoms in the face of the crystal—in this case, a (111) face which has been etched by vaporisation.