A low energy electron beam of 54eV was shot at a piece of nickel. The piece of nickel could be rotated so they could
see how the diffraction was depended on the angle. An electron detector was used so it could observe the electrons at different angles. At certain angles there were peaks in the intensity and others there were lows.
This shows that the electrons were exhibiting wavelike properties. They used the formula 2dSin(a)=nLambda (Bragg's law) where d
is the separation between two planes of the crystal lattice, a is the angle between the electron beam and the surface of the crystal lattice, Lambda is the wavelength and n
is the quantum number. They also used the de Broglie wavelength equation, Lambda=h/p where h is plank's constant and p is the linear momentum (p=mv). With these equations they developed the
expression.
With this equation, they were able to predict the location of the
maxima and minima which shows that the electrons exhibited properties similar to waves.
For more information on the experiment and the theory behind it, go to:
