Nuclear Magnetism in Metals

Nuclear magnetism in elemental metals is discussed with the emphasis on spontaneous nuclear ordering. Materials feasible for experiments are classified according to the abundancies of magnetic and non-magnetic isotopes which crucially affect their physical properties. The Hamiltonian of these systems consists of the dipolar interaction and the conduction electron mediated indirect interaction. The theory and measurement of indirect spin-spin coupling are described. Copper is still the only metal in which spontaneous nuclear ordering has been observed; the experiments are briefly reviewed. The structure of the observed three antiferromagnetic phases is discussed. A spin-wave calculation predicts a novel antiferromagnetic structure for the ground state. Phase diagrams for silver and gold in a magnetic field are expected to be drastically different from that of copper.