Chapter 2 Magnetic materials studied by muon spin rotation spectroscopy

Abstract

This chapter discusses the results on magnetic materials obtained by a single technique— namely, muon spin rotation (μSR) spectroscopy. The magnetic properties of certain materials as collected by different methods and techniques are focused in the chapter. The application of μSR-spectroscopy has added to the understanding of established magnetic phenomena. However, when using positive muons (μ + ) μSR spectroscopy has shown the potential to uncover new and unexpected magnetic features owing to its high sensitivity to small magnetic fields and spatially inhomogeneous properties. Thus μSR-spectroscopy is most powerful in the field of small moment magnetism and in all instances when magnetic order is of a random or short range nature and where neutron scattering will fail. The μSR-spectroscopy also works in the case of broad lines and short relaxation rates. The local probe aspect of μSR and its sensitivity to inhomogeneous features has brought the real nature of solids into light that are never perfect in lattice structure, stoichiometry, and morphology; and hence also magnetic properties do not show up in an ideal manner. To perform μSR measurements, positive muons have to be implanted into the material of interest.