  Oxygen chain fragments are known to appear at the insulator to superconductor
transition (SIT) in YBa2Cu3O6+y. However the self organization and the size
distribution of oxygen chain fragments is not known. Here we contribute to fill
this gap, using scanning micro X ray diffraction which is a novel imaging
method based on advances in focusing synchrotron radiation beam. This novel
approach allows us to probe both real-space and k-space of a high-quality
YBa2Cu3O6.33 single crystals with Tc=7K. We report compelling evidence for
nanoscale striped puddles, with Ortho-II structure, made of chain fragments in
the basal Cu(1) plane with local oxygen concentration 0.5. The size of the
Ortho-II puddles spans a range between 2 and 9 nanometers. The real space
imaging of Ortho-II puddles granular network shows that superconductivity, at
low hole-doping regime, occurs in a network of nanoscale oxygen ordered
patches, interspersed with oxygen depleted regions. The manipulation by thermal
treatments of the striped Ortho II puddles has been investigated focusing on
the spontaneous symmetry breaking near the order to disorder phase transition
at 350 K.
