The oxygen interstitials in the layers separating the superconducting CuO2 planes undergo ordering phenomena in La2CuO4+y that enhance the transition temperature (Tc). It is also known that complex systems often have a scale-invariant structural organization, but hitherto none had been found in high-Tc materials. These authors report that the ordering of oxygen interstitials in the La2O2+y spacer layers of La2CuO4+y high-Tc superconductors is characterized by a fractal distribution up to a maximum limiting size of 400 µ.
- Michela Fratini
- Nicola Poccia
- Antonio Bianconi
