ELECTROCHEMICAL ROOM-TEMPERATURE REDUCTION AND REOXIDATION OF THIN-FILMS AND PELLETS OF YBA2CU3O7-X

YBa2Cu3O7 (1237) was reduced and reoxydated quantitatively, in a contr olled manner, at room temperature (RT),by way of extraction or inserti on of oxygen, using an electrochemical set-up. RT reduction and reoxyg enation of thin films, which led to homogeneous products, as judged by X ray diffraction. Since reduction leads to loss of superconductivity and re-oxidation restores it, this method allows room temperature con trol over superconducting properties of (parts of) films. This permits patterning of (1237) thin films. SNS-like structures were already pre pared by this method. The method affords control not only over n(E(F)) via [oxygen]bulk, but also over the quality of the intergranular cont act, possibly via control of [oxygen] in the outermost layers of grain s (in films and pellets).