Doping the high-Tc superconductor YBa2Cu3O6.7 with 1.5 % of non-magnetic Zn impurities in CuO2 planes is shown to produce a considerable broadening of 63Cu NMR spectra, as well as an increase of low-energy magnetic fluctuations detected in 63Cu spin-lattice relaxation measurements. A model-independent analysis demonstrates that these effects are due to the development of staggered magnetic moments on many Cu sites around each Zn and that the Zn-induced moment in the bulk susceptibility might be explained by this staggered magnetization. Several implications of these enhanced antiferromagnetic correlations are discussed.
@article{arxiv.cond-mat/9911194,
title = {Cu NMR evidence for enhanced antiferromagnetic correlations around Zn impurities in YBa2Cu3O6.7},
author = {M. -H. Julien and T. Feher and M. Horvatic and C. Berthier and O. N. Bakharev and P. Segransan and G. Collin and J. -F. Marucco},
journal= {arXiv preprint arXiv:cond-mat/9911194},
year = {2009}
}