Advantages of Neutron Diffraction:

It is an important tool in the investigation of the magnetic ordering that occurs in some materials. Light atoms (say H) are better resolved in a neutron pattern. However, they do not contribute significantly to an X-Ray diffraction pattern.

Because they are neutral, neutrons do not interact with electrons in the crystal.So, unlike X-Rays, which are scattered entirely by electrons, neutrons are scattered entirely by nuclei.

Although uncharged, neutrons have an intrinsic magnetic moment, so they will interact strongly with atoms & ions in the crystal which also have a magnetic moment.

Neutrons are more useful than X-rays for determining the crystal structures of solids containing light elements.

Neutron sources in the world are limited so neutron diffraction is a very special tool & is very expensive.