Staggered magnetization inLa2−xSrxCuO4fromLa139NQR and μSR: Effects of Sr doping in the range 0<x<0.02

We have used ${}_{}{}^{139}{}_{}{}^{}\mathrm{La}$ nuclear quadrupole resonance (NQR) and positive muon spin rotation (μSR) measurements to probe the weakly doped antiferromagnetic (AF) region (x30 K, is found from both the NQR and μSR measurements to follow the same empirical relation ${\mathit{M}}^{\mathrm{°}}$(x,0)/${\mathit{M}}^{\mathrm{°}}$(0,0)=(1-x/${\mathit{x}}_{\mathit{c}}$${)}^{\mathit{n}}$ with ${\mathit{x}}_{\mathit{c}}$=0.023 and n=0.236. To model the extrapolated values, we assume that the doped holes are mobile and are situated in 1D ‘‘rivers’’ of charge which form walls in the ${\mathrm{CuO}}_2$ planes and which separate and uncouple undoped AF domains; an infinite number of these layers are stacked along the c axis.