UC Irvine

We report muon-spin-relaxation studies in the Li-doped cuprates (Formula presented)(Formula presented)(Formula presented)(Formula presented) for x=0.01, 0.05, 0.10, 0.45, and 0.50. For low Li concentrations (x⩽0.10) we find a rapid suppression of (Formula presented) as x increases, but little change in the magnitude and temperature dependence of the antiferromagnetic order parameter. This indicates that Li doping effectively destroys antiferromagnetism (similar to Sr doping, but different from Zn doping) without strongly affecting either the on-site Cu moments or the shape of the spin-wave excitation spectrum. For high Li concentrations we find that the majority of the sample volume is nonmagnetic, suggesting possible singlet-state formation. © 1996 The American Physical Society.