We report a Cu nuclear quadrupole resonance experiment on magnetic impurity Ni-substituted YBa2Cu3-xNixO7-δ. The distribution of Ni-substituted sites and its effect on the Cu electron spin dynamics are investigated. Two samples with the same Ni concentration x = 0.10 and nearly the same oxygen content but different Tc's were prepared: One is an as-synthesized sample (7-δ=6.93) in an oxygen gas (Tc≈80 K), and the other is a quenched one (7-δ= 6.92) in a reduced oxygen atmosphere (Tc≈70 K). The plane-site 63Cu(2) nuclear spin-lattice relaxation for the quenched sample was faster than that for the as-synthesized sample, in contrast to the 63Cu(1) relaxation that was faster for the as-synthesized sample. This indicates that the density of plane-site Ni(2) is higher in the quenched sample, contrary to the chain-site Ni(1) density, which is lower in the quenched sample. From the analysis in terms of the Ni-induced nuclear spin-lattice relaxation, we suggest that the primary origin of suppression of Tc is associated with the nonmagnetic depairing effect of the plane-site Ni(2).
|Number of pages||5|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2002 Oct 1|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics