Variation of the oxygen content in YBa/sub 2/Cu/sub 3/O/sub 7-x/ films deposited by high oxygen pressure DC-sputtering

The authors have investigated the effect of the variation of the oxygen deficiency on critical temperature, T/sub c/, and the normal-state resistivity rho (T) of high-quality [001]- and [110]- or [103]-oriented epitaxial YBa/sub 2/Cu/sub 3/O/sub 7-x/ films deposited by high-oxygen-pressure DC-sputtering. Oxygenation in a microwave oxygen plasma can increase T/sub c/ to up to 95 K and completely restores the film properties suppressed by deoxygenation in molecular oxygen at the same pressure and temperature conditions. The second derivative of the normal-state resistivity has a higher value for the nearly fully oxygenated films and better microstructure. A linear dependence rho (T>150 K) was received for an oxygen deficiency of about 0.1 or for nearly fully oxygenated films with a less perfect microstructure.<
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