DOI: 10.1051/jp1:1996209
J. Phys. I France 6 (1996) 2205-2236

NMR Studies of the Normal State of High Temperature Superconductors

C. Berthier^{1, 2}, M.H. Julien², M. Horvatic² and Y. Berthier<sup>1

1</sup>  Laboratoire de Spectrométrie Physique, UR CNRS 5588, Université Joseph Fourier, Grenoble I, BP 87, 38402 Saint-Martin d'Hères Cedex, France
²  Grenoble High Magnetic Field Laboratory, Centre National de la Recherche Scientifique and Max Planck Institut für Festkörperforschung, BP 166 X, 38042 Grenoble Cedex 9, France

(Received 19 July 1996, received in final form 29 August 1996, accepted 30 August 1996)

Abstract
We review NMR and NQR studies in the normal state of high- superconducting cuprates. Emphasis is given on the three major contributions brought by these techniques: the presence of antiferromagnetic fluctuations, the possible justification of a single spin fluid model, and the opening of a pseudogap in the spin excitations for underdoped compounds. Some recent developments are addressed and compared to theoretical models. In particular, quantitative analysis of the nuclear relaxation are detailed for ⁶³Cu, ⁸⁹Cu, ¹⁷O nuclei, enabling a comparison with inelastic neutron scattering data, and finally pointing out to a serious difficulty with the one-band approach.

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