Localized behavior near the Zn impurity in YBa2Cu4O8 as measured by nuclear quadrupole resonance - art. no. 104506

We have performed Cu-63,Cu-65 nuclear quadrupole resonance measurements on Zn-substituted YBa2Cu4Odelta. We find that the spin-lattice magnetization r ecovery from the nearest-neighbor Cu and the bulk Cu sites cannot be fitted to a single exponential. Furthermore, the spin-spin magnetization decay fr om the Cu sites that are nearest neighbor to the Zn impurity does not follo w the expected Gaussian decay while the spin-spin magnetization decay from the remaining sites is Gaussian. We show that the data can be consistently interpreted in terms of localized charge and spin predominately on the Cu s ites that are nearest neighbor to the Zn impurity. There is no evidence of an extended suppression of the antiferromagnetic correlations near the Zn i mpurity or a transition from magnetic to quadrupole relaxation with increas ing Zn impurity concentration.