Davisson-Germer experiment

The Davisson-Germer experiment is considered an unequivocal demonstration of the wave nature of matter and a fundamental demonstration of the viability of the theory of quantum mechanics. In 1927, Clinton Joseph Davisson (1881-1958) and Lester Halbert Germer (1896-1971) tested de Broglie’s hypothesis of the wave behaviour of matter by beaming electrons at varying levels of energy at a crystal lattice of nickel. Since the sample of nickel was composed of layers or planes of crystals at regular intervals, the expectation was that the electrons would be scattered at varying angles from the crystal layers. Subsequently, the electrons scattering from the different planes would then interfere with each other.

Davisson and Germer then measured the current (energy) and angle of the scattered electrons. Their data showed clear evidence of interference patterns typical of waves and those patterns were correlated with the different planes of the crystals. See the following references for historical discussions: Refs.