title: Impurity-induced local magnetism and density of states in the superconducting state of YBa2Cu3O7.
abstract: 17O NMR is used to probe the local influence of nonmagnetic Zn and magnetic Ni impurities in the superconducting state of optimally doped high TC YBa2Cu3O7. Zn and Ni induce a staggered paramagnetic polarization, similar to that evidenced above TC, with a typical extension xi=3 cell units for Zn and xi>or=3 for Ni. In addition, Zn is observed to induce a local density of states near the Fermi energy in its neighborhood, which also decays over about 3 cell units. Its magnitude decreases sharply with increasing temperature. This allows direct comparison with the STM observations done in BiSCCO.
authors.affiliation: Laboratoire de Physique des Solides, UMR8502, Université Paris XI, 91405 Orsay, France.
authors.forename: S
authors.initials: S
authors.lastname: Ouazi
authors.forename: J
authors.initials: J
authors.lastname: Bobroff
authors.forename: H
authors.initials: H
authors.lastname: Alloul
authors.forename: M
authors.initials: M
authors.lastname: Le Tacon
authors.forename: N
authors.initials: N
authors.lastname: Blanchard
authors.forename: G
authors.initials: G
authors.lastname: Collin
authors.forename: M H
authors.initials: MH
authors.lastname: Julien
authors.forename: M
authors.initials: M
authors.lastname: Horvatić
authors.forename: C
authors.initials: C
authors.lastname: Berthier