Abstract
YBa2Cu3Oy with the perfectly ordered Cu1 planes was successfully prepared in the wide composition range of y by slowly cooling in O2 and N2 gases, and the superconductive properties were examined. By "perfect order", one means that the a-sites are empty and the b-sites are fractionally, randomly occupied by oxygen. From resistivity measurement under magnetic fields, the superconductive properties of oxygen deficient YBa2Cu3Oy seem to be composed of two components. The two components may be related to the electronic states of the Cu2 and Cu1 planes.
