  Light hole doping of lanthanum cuprate strongly suppresses the onset of
antiferromagnetic (AF) order. Surprisingly, it simultaneously suppresses the
extrapolated zero temperature sub-lattice magnetization. 139La NQR results in
lightly Li-doped lanthanum cuprate have demonstrated that these effects are
independent of the details of the mobility of the added holes. We propose a
model in which doped holes phase separate into charged domain walls that
surround ``anti-phase'' domains. These domains are mobile down to ~30 K where
they either become pinned to the lattice or evaporate as their constituent
holes become pinned to dopant impurities.
