Electron diffraction
$1.00
Principle
Fast electrons are diffracted from a polycrystalline layer of graphite: interference rings appear on a fluorescent screen. The interplanar spacing in graphite is determined from the diameter of the rings and the accelerating voltage.
Benefits
Experience the essence of the Nobel Prize: de Broglie (1929)
Impressive visualization of a Nobel Prize experiment with various changeable parameters
Simple setup
Easy determination of the interplanar spacing of graphite
Perfect demonstration of wave-particle duality
Tasks
To measure the diameter of the two smallest diffraction rings at different anode voltages.
To calculate the wavelength of the electrons from the anode voltages.
To determine the interplanar spacing of graphite from the relationship between the radius of the diffraction rings and the wavelength.
Learning objectives
Bragg reflection
Debye-Scherrer method
Lattice planes
Graphite structure
Material waves
De Broglie equation
