β Emitters and Isomeric Nuclei as Probes in Condensed Matter

This chapter surveys the behaviour of radioactive probe nuclei with lifetimes in the range of τN ≈ 10 −5 – 103 s condensed matter. Not only hyperfine interactions (hfi) play a role in the experiments to be reported here, but all interactions of the probe’s nuclear moments with electromagnetic fields. An important example is the nuclear dipole-dipole interaction. In order to restrict the length of this review we consider only experiments where the probe nuclei have been created and oriented “in-beam”, i.e., by reactions with a particle beam during the course of the measurement. Thus, the important area of low temperature nuclear orientation (τN ≳ 1 h) is omitted here, but this has been excellently treated in several recent reviews [6.1,2]. We discuss here all in-beam experiments using β emitting nuclides (τN ≈ 10−2 – 103 s) in condensed matter. Further, those in-beam experiments using isomeric γ emitters are reviewed, where nuclear magnetic resonance (NMR) signals were observed or where spin-lattice relaxation phenomena — mostly in liquid metals — were investigated (τN ≈ 10−5 – 10−2 s)The many other experiments applying short-lived γ active nuclei to solid state studies have been discussed in Chaps.4 and 5.