Abstract
We have carried out elastic, quasielastic (), and inelastic neutron scattering studies of the antiferromagnetic spin correlations in with varying between 0.02 and 0.18. The crystals, which were grown in three different laboratories, exhibit behavior that varies smoothly with . In all cases, antiferromagnetic correlations with a scattering amplitude corresponding to a fully occupied square lattice are observed. However, the Néel state is destroyed by the doping and the spin-spin correlation length is quite short, varying from ∼35 to ∼8 Å as varies between 0.02 and 0.18; the local order is, however, the same as in pure Cu. The fluctuations are dynamic in character as in Cu above the Néel temperature . To a first approximation, Å, the average separation between the holes introduced by the doping. The sample exhibits superconductivity with K and with a Meissner fraction exceeding 15% at 5 K; no important differences in the magnetic scattering are observed in the normal and superconducting states. In an appendix we present additional data on the spin dynamics in pure Cu at K in a sample with K.
- Received 20 April 1988
DOI:https://doi.org/10.1103/PhysRevB.38.6614
©1988 American Physical Society