Nuclear magnetic resonance and electron spins: Some history, ancient and in the making

Scaling relationships for Nmr spin-lattice relaxation time T 1 and Gaussian transverse relaxation tme T 2G c reviewed and applied to analyse experiments in the normal state of YBa2Cu4O8. Studies of T 2G in the superconducting state are analysed using the theory of Pines and Wrobel to show a preference for d-state orbital pairing over anisotropic s-state. Data on 13C Nmr in the normal and superconducting state of the two dimensional organic conductor (ET)2Cu[N(CN)2]Br are presented and shown to have great similarity to that of the cuprates.