MU-SR STUDIES OF LI-DOPED LA2CUO4

Magnetic properties of the Li-doped cuprates La2Cu1-xLixO4 (where x = 0.01, 0.05, 0.10, 0.45, and 0.50) have been studied by mu SR. For low Li concentrations (x less than or equal to 0.10) we find a rapid suppr ession of T-N as x increases, but little change in the magnitude and t emperature dependence of the AFM order parameter. This indicates that Li doping effectively destroys AFM (similar to Sr doping, but differen t from Zn doping) without strongly affecting the onsite Cu moments and the shape of the spinwave excitation spectrum. For high Li concentrat ions we find magnetic clusters in about 15% of the sample volume; the remaining volume is non-magnetic, suggesting possible singlet-state fo rmation.