CHARGE-SPIN FREEZING AND FINITE SIZE SCALING IN YBa2Cu3O6+x

The charge and spin freezing phenomena in high TcYBa2Cu3O6+x superconductor is investigated in the low doping region (0 0.2, the observed spin freezing is correlated to the charge freezing of the holes in the Cu(2)O2 planes. The data may be fitted to a model of size-dependent reduction of the staggered magnetization implied in a stripe scenario. The hole concentration dependence of these freezing phenomena is mapped onto the phase diagram of YBa2Cu3O6+x.