EFFECTS OF ELECTRON-ELECTRON INTERACTIONS ON NUCLEAR SPIN-LATTICE RELAXATION RATES AND KNIGHT SHIFTS IN ALKALI AND NOBLE METALS

Nuclear-magnetic-resonance data for the alkali and noble metals are discussed in terms of Moriya's theory of exchange-enhanced spin-lattice relaxation rates. The available evidence suggests that the relaxation-rate enhancement resulting from collective electron effects is 20% smaller in lithium and sodium than predicted by the theory for the case of a -function-potential electron-electron interaction. This small disparity is attributed to a nonzero interaction range whose magnitude is estimated to be less than an atomic radius. During the course of this study, low-temperature Knight-shift and spin-lattice relaxation data have been obtained for K39, Rb85, Rb87, and Cs133 in the respective metals. The results suggest that the exchange enhancements of the conduction-electron spin susceptibilities in these metals are comparable to those in lithium and sodium. Similar conclusions apply in the case of the noble metals. © 1968 The American Physical Society.