Davisson and Germer further investigated properly oriented crystals to observe if could be possible to interpret that electron behave as waves of all wave lengths (λ) as given by De–Broglie's hypothesis.

To prove the same, the two scientists Davisson and Germer designed and built a vacuum apparatus for the purpose of measuring the energies of electrons scattered from a metal surface. A beam of electrons emitted by the electron gun is made to fall on Nickel crystal cut along cubical axis at a particular angle. The scattered beam of electrons is received by the detector which can be rotated at any angle.

The sharp peak in the intensity of the electron beam in a particular direction is due to the constructive interference of electrons scattered from different layers of regularly spaced atoms of the nickel crystal. i.e., diffraction of electrons takes place. This confirms the wave nature of moving electron.