Title :
Variation of the oxygen content in YBa/sub 2/Cu/sub 3/O/sub 7-x/ films deposited by high oxygen pressure DC-sputtering
Author :
Faley, M.I. ; Poppe, U. ; Soltner, H. ; Dahne, U. ; Klein, N. ; Schulz, H. ; Evers, W. ; Urban, K.
Author_Institution :
Inst. fur Festkorperforschung, Forschungszentrum Julich GmbH, Germany
fDate :
3/1/1993 12:00:00 AM
Abstract :
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.<>
Keywords :
barium compounds; crystal microstructure; electrical conductivity of crystalline semiconductors and insulators; high-temperature superconductors; sputtered coatings; stoichiometry; superconducting epitaxial layers; superconducting transition temperature; yttrium compounds; 95 K; YBa/sub 2/Cu/sub 3/O/sub 7- delta /; critical temperature; deoxygenation; films; high oxygen pressure DC-sputtering; high quality epitaxial films; high temperature superconductors; microstructure; microwave oxygen plasma; normal-state resistivity; oxygen content; oxygen deficiency; oxygenated films; Conductivity; Copper; Electromagnetic heating; Microwave ovens; Oxygen; Plasma measurements; Plasma temperature; Sputtering; Substrates; Superconducting films;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
