Y. Scolnik et al., ELECTROCHEMICAL, ROOM-TEMPERATURE REDUCTION, OXIDATION AND MICROSCOPIC PATTERNING OF MULTINARY CUPRATE SUPERCONDUCTORS, JPN J A P 1, 32, 1993, pp. 683-685
YBa2Cu3O7 (1237) was reduced and reoxidized at room temperature (RT),
by using wet electrochemistry to extract, or solid state electrochemis
try to re-insert oxygen. With thin films this led to homogeneous produ
cts, as judged by X ray diffraction and temperature dependence of elec
trical resistivity. Because reduction leads to loss of superconductivi
ty and re-oxidation restores it, this method allows room temperature c
ontrol over superconducting properties of (parts of) films and, thus,
can be used for patterning of (1237) thin films. We showed this by pre
paring SNS-like structures by this method. The method affords control
not only over bulk properties, but also over the quality of the interg
ranular contact, possibly via control of oxygen concentration and orde
ring in the outermost layers of grains (in films and pellets). The res
ults imply rapid, field-assisted, oxygen motion and this was confirmed
by independent measurements.