Magnetic behavior in Li-doped La2CuO4

We report muon-spin-relaxation studies in the Li-doped cuprates La2Cu1-xLixO4 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 TN 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.