Heavy ion reactions in the study of hyperfine interactions in solids

Isomeric excitation of nuclear states with pulsed heavy-ion beams by fusion reactions and the observation of magnetic and quadrupole spin precession of these states in solid state multipole fields, have had a strong impact on the study of hyperfine interactions in solids in recent years. The experiments address the general areas of research covered by other techniques such as Moessbauer effect and NMR and, more particularly, muon spin rotation. Unique advantages offered by the heavy-ion techniques have considerably extended the scope, detail and range of systematic investigations well beyond the capabilities of radioactivity and light ion reaction experiments. This survey will assess this impact by a series of case studies of various problems in nuclear and solid state physics which have benefited by use of heavy ion reactions. These include: determination of quadrupole moments of high spin isomers, measurement and characterization of hyperfine magnetic fields at impurities in 3d and rare earth ferromagnetic hosts, electric field gradients in metals, studies of valence instability of rare earth ion systems etc. Future prospects of this research especially in the light of the commissioning of several new heavy-ion research facilities around the world, will be briefly commented on. (author)