Spinless impurities in high-T-c cuprates: Kondo-like behavior

We compare the effects of in-plane nonmagnetic Li+ and Zn2+ impurities on t he normal state of high-T-c cuprates. Y-89 NMR shows that the extra hole in troduced by Li is not localized in its vicinity. The T-c depression and ind uced moments on near neighbor Cu sites of Zn or Li are found to be identica l. These effects of spinless impurities establish the major influence of th e spin perturbation with respect to the charge defect. The susceptibility o f the induced moment measured by Li-7 NMR displays a 1/(T + Theta) behavior , Theta Increases with doping up to about 200 K in the overdoped regime. We attribute this to a "Kondo-like" effect.