In addition to X - rays, neutrons and electrons can also be used in diffraction techniques by carefully choosing their wavelengths to lie between 10 pm to 200 pm. The wavelength
of any object may be obtained from the de Broglie relation
= h / p where h is Planck's constant and p, the momentum of the particle.
The wavelength of thermal neutrons can be obtained by using the thermal value of p = (m k T ) 1/ 2. Neutrons interact with the atomic nuclei and can sensitively detect the presence of hydrogen atoms as well as distinguish atoms of similar electron densities such as Co and Ni. The bond lengths of C - H ( 109 pm ) and O - H ( 97 pm ) estimated by neutrons are more accurate than the X - ray results. Furthermore, since neutrons have a spin ( spin angular momentum of
/ 2), they can distinguish magnetically different atoms of the same substance and are very useful in the study of lattices wherein there is magnetic (spin) ordering
Electron diffraction is useful when the number of scattering centers are fewer, as in the case of molecules in the gas phase as well as the surfaces of solids. Electron diffraction has been used to estimate interparticle separations in molecules as well as the structures of the surfaces of solids.
of any object may be obtained from the de Broglie relation
= h / p where h is Planck's constant and p, the momentum of the particle. 
/ 2), they can distinguish magnetically different atoms of the same substance and are very useful in the study of lattices wherein there is magnetic (spin) ordering 
