Nuclear magnetic resonance in high-Tc superconductors

This paper is aimed at the nonspecialist in nuclear magnetic resonance who wants to know what NMR can do to increase his understanding of high-T
c
superconductors. Most NMR results are discussed in an illustrative manner to facilitate intuitive understanding. Several specific NMR experiments are presented which demonstrate the variety of this experimental technique. Special emphasis is given to the following aspects: ionic charges and quadrupole interaction, local fields and magnetic ordering, conduction electrons and Knight shifts, quasiparticle excitations, and nuclear spin-lattice relaxation.