For investigation of many systems, muons provide a complementary probe to techniques such as neutron scattering. This is particularly true for studies of magnetic systems - the diagram shows how the fluctuation rates that muons probe can complement those accessible to neutron scattering. Muons are particularly good for investigations where magnetism is weak or dilute - they are a very sensitive probe! For the case of superconductors, as well as being able to explore atomic-level magnetism associated with superconductivity, muons provide an important probe of flux lattice behaviour, and can give information complementary to small angle neutron scattering.

There are other reasons why muons may be the best technique to use for a given sample. For example, the muon method can be used in zero applied field, whereas NMR would require application of fields which may affect sample properties. In cases where the behaviour of the muon itself is of interest, such as when using muons as proton analogues to study hydrogen behaviour, undoped, intrinsic samples can be used.

Fluctuation rates accessible to various techniques. Muons bridge the gap between neutron scattering and NMR methods.