Magnetic fluctuations in La sub 1. 95 Ba sub 0. 05 CuO sub 4 (FR)

Neutron-scattering and resistivity experiments on single crystals of La{sub 1.95}Ba{sub 0.05}CuO{sub 4} are described. On warming to as high as 250 K, the correlation length does not change, and the temperature dependence of the generalized susceptibility {chi}({ital Q},{omega}) is due solely to the temperature-dependence of the local response. We show that the associated relaxation rate in the metallic regime is {h bar}{Gamma}{congruent}1/2{ital k}{sub {ital B}T}, in accord with the marginal-Fermi-liquid hypothesis, and relate our results to nuclear spin-lattice relaxation data.