Charge-Spin Freezing and Finite Size Scaling in YBa2Cu3O6+x

The charge and spin freezing phenomena in high Tc YBa2Cu3O6+x superconductor is investigated in the low doping region (0<x<0.4) by the zero-field muon spin relaxation (ZF-μSR) technique. For x>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.